# 65 GTO Wheel Size



## renorealtors (Apr 7, 2018)

I am at the point of ordering wheels and wonder what is the go to size for wheels and tires on a GTO with big brakes. I think 17" will fit but there has to be a size that will give me the most width but not rub. My 65 Chevelle was tight but 18" IROC looking wheels fit on it with just a bit of rub in tight turns. Does anyone have any ideas or been there choosing sizes? I took my Z06 front wheel off and tried to fit it but it was way to wide?


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## cij911 (Oct 25, 2017)

I just ordered 17x8 & 17x9.5 AR Torq II.....


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## renorealtors (Apr 7, 2018)

You have to let me know how they work out?? How did you come up with the size and offsets??


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## Joe'sToy (Mar 9, 2012)

Okay, I have posted my results in another post about "Rim" size and tire size. I am running 17"x9.5" in the rear and 17"x8" in the front. Tires are 275x40x17 in the rear and 225x45x17 in the front and absolutely no rubbing issues anywhere. I am running stock suspension for now, but just ordered a coil over kit from Viking, which I'll install as soon as it comes in.


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## cij911 (Oct 25, 2017)

Joe'sToy said:


> Okay, I have posted my results in another post about "Rim" size and tire size. I am running 17"x9" in the rear and 17"x8" in the front. Tires are 275x40x17 in the rear and 225x45x17 in the front and absolutely no rubbing issues anywhere. I am running stock suspension for now, but just ordered a coil over kit from Viking, which I'll install as soon as it comes in.


Hey Joe! I too am looking at the Viking coilovers. Who did you buy them from and what bring rates did you get ? (I am considering the 550# front & 150# rear.) I also will be installing inexpensive front upper and lower control arms (ebay) and Spohn rear del sphere (think heim joint) arms, along with new centerlink and inner and outer tie rods.


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## Joe'sToy (Mar 9, 2012)

The Viking kit I ordered is for a GM "A" body, '64-67'. The springs in this kit are street springs as I'm not racing and or auto crossing. I think you can get it with either regular or big block springs, depending on your motor. I am using my stock A arms and not replacing them. On the rear setup, re-using my original stuff as well. Already boxed and new bushing in my 4 link a couple of years ago and all are still in great shape. The main reason I am doing this is for stance and ride quality, the rear coil overs come with a two position setup for the shock, then you can adjust away to fine tune it after. The front I'm looking at dropping an inch to 2 inches and that is enough for me.


I ordered this kit through a local Resto shop, who are a dealer for Viking, and they ordered directly from Viking, so I got the dealer price which is nice. Remember, up here we have to pay tax, import duties and exchange rate on the dollar, so it adds up.

I'm away from home right now for work, doing training for a customer who just bought new Co-gen generator system, from my company, We're a CAT Dealership, so when I get back home this week, I'll find my order sheet and post the details.


Joe.


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## cij911 (Oct 25, 2017)

renorealtors said:


> You have to let me know how they work out?? How did you come up with the size and offsets??


American Racing determined the fit. I should have them installed next week and will let you know.


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## Joe'sToy (Mar 9, 2012)

cij911 said:


> Hey Joe! I too am looking at the Viking coilovers. Who did you buy them from and what bring rates did you get ? (I am considering the 550# front & 150# rear.) I also will be installing inexpensive front upper and lower control arms (ebay) and Spohn rear del sphere (think heim joint) arms, along with new centerlink and inner and outer tie rods.


cij911,

I found this on-line, this is the kit I ordered. Front spring rate is 550 and the rear is 150. Once I get it and installed, I'll post up, before and after.

Joe.


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## Joe'sToy (Mar 9, 2012)

renorealtors said:


> You have to let me know how they work out?? How did you come up with the size and offsets??


You'll need a BS of at least 5" in the rear and 4.75" in the front, if your using 17" rims. I have attached a page from another forum, that covers what guy's are doing with rim and tire size.

"I have a 65 (but identical to 64). I have 235/45/17 on front and 255/50/17 on rear . Wheels are 17X8 with 4.5" backspacing all the way around. If I were to do it again I would go with 5" of backspacing on the rear, had to roll quarter lip slightly to fit.


I went with Torque Thrust II's on mine. 16x8 on all four corners with a 4.75 backspacing. I also went what some would consider conservative on the tire sizing. 235/60x16 in the rear to get the stock 27.1 diameter. 215/55x16 on the fronts. The additional height was not wanted, and larger tires would have hit when turning. I also added Hotchkiss lowered coils with an additional 1/2 coil removed. I have plenty of clearance on turns, and in the rear wheel wells. Just about 1/2 inch on the inside and outside.


Here's a shot of my own '64 Tempest that rolls on 17X8" rims (4-1/2" backspace) shod with 235/45-17s.


Torq Thrust IIs 17X8. 4.75" Backspacing. 235/45/17 tires all around.


I have 15X8 w/ 4.75 backspace and 275-60-15s on the rear of my 65 (same body as 64s) and they are tight - have about 1/2 inch clearance to the fenderlip and about 3/4" between the tire and frame on the inside. Tight but it doesn't rub!


I've got a newer 12 bolt (1" wider) in my 65 and went with a 15 x 8 with 5.25 backspacing for the rear. Didn't think a 275 would fit without rolling the lip so went with a 255 width.


If you have the original rear you should run P275/60R15's on a 15x8 rim with a 4 1/2" backspacing. If you are running a later year rear end you can run the same tires but use a 5" backspacing because the overall width of later rears are wider. I'm running P275/60R15's on the back of my 65 that has a later 69ish rear. I'm using a 15x8 rim with a 4 1/2" backspacing and 0ne side just touches the inside lip of the wheel opening slightly. If I had a 5" backspace they wouldn't touch at all.


I am having similar rubbing problems with 17x8 (4.5" BS) wheels on my '65 Lemans. Tires (245/45) rub on rear lower lip of the front fenders, and a little on the upper lip when the suspension compresses.


15x8" front & rear. 4.5" backspacing front - 4.75" backspacing rear. 235-60x15 front, 255-60x15 rear. (275-60x15 should work in the rear with 5" backspacing).


Boyd 16X8 with 5 1/8", 245/50-16 front and rear, and 255 may fit.


Rear Axle on my 65 GTO (from a '65 Chevelle 12-bolt) is 60 inches wide measured from the outboard edge of flange to flange. My 15x8 wheels use 5 inch backspacing to center a 275x60x15 nicely in the wheel well.


I run a set of 235/45-17s on 8" wide wheels all around on a '64 Tempest (same wheelwells as a '65). The wheels have a 4-1/2" backspace and sit a bit towards the outside of the wheelwells for a wider stance. I know 245/45-17s would fit in back, up front they would probably interfere a bit on the outer part of the inner fender near the fender lip on big bumps. I am running a stock width rear axle.


To better center the rear wheels in the wells a 5" backspace would be ideal. I think you could use a 255/40-18 and have a good fit on the 18X8" wheel with a 5" backspace. Up front if you want to use a 17X7" wheel a 4-1/2" backspace would be close to ideal, a 235/45-17 tire would be a good fit. If you decide to use a 17X8" up front you could use a 5" backspace and tuck a 245/45-17 in there.


17x8 wheels with 4.5" backspacing WILL rub on a 65 if you have 245/45-17 tires on the front. B-man is right--a 5" backspace on the front would do the trick. I have the same tires with 4.5" backspace on the rear and there's plenty of room.


I have 17x8 on the front, 5.25" BS, 245/45-17. On the rear are 17x9.5, 5.75" BS, 275/40-17. This is a 65 Lemans, no alterations whatsoever on the wheelwells. I do have Baer brakes front and rear which push the wheel mounting flange out about 1/4," so subtract 1/4" from the backspacing numbers if you have stock brakes. This wheel combo looks and performs fantastic! I didn't think I could get so much tire in back, but a friend clued me into the correct backspacing, and it's available as a custom order on the American Racing TT2.


I ended up with 235/60/15 front, and 245/60/15 out back on rims with 4 3/4 backspacing. The fronts fit nice with no rubbing and a nice diameter, the back also looks great, nice width. If you really want all 4 the same then 235/60/15 tires are the way to go.


No rubbing at all with 9” wide 18” rims. Once had 9.5” wide rims and they JUST cleared. That is the max with a 255/45/18 tire. With 17s, you can run 8” wide with 4.75” backspacing all the way around and then be able to rotate the tires. Use 245/45 all the way around or go 50 series in the rear. Out back, a 9” wide 17” rim with 5” backspacing should be okay with a 245/45/17.


The fronts are 8" wide w/ 5" backspacing with 245/40 -8 tires (could use 4.75" b/s and would be ideal). The rears are 9" wide with 5.10" backspacing and 255/45 -18" tires. Also, rim backspacing depends on your rearend width (64-66 year width or a later on which is 1" wider) and if you have disc brakes. I am also doing a 65 GTO with 4 wheel discs & Hotchkis springs but may have to use 2" dropped front spindles to get it to sit like the Tempest. The rims are the same width but the rear rims have 5.20" backspacing.


17" Torque Thrust II's - 8" wide rims up front and 9.5" rims at rear. The rear rims are special order from AR with 5.875" backspacing and the fronts are off-the-shelf, but I had to get them backspaced further as the tires rubbed. Tires are 275's out back and 245's up front."


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## renorealtors (Apr 7, 2018)

Lots of great info! 

I have 17x8 on the front, 5.25" BS, 245/45-17. On the rear are 17x9.5, 5.75" BS, 275/40-17. This is a 65 Lemans, no alterations whatsoever on the wheelwells. I do have Baer brakes front and rear which push the wheel mounting flange out about 1/4," so subtract 1/4" from the backspacing numbers if you have stock brakes. This wheel combo looks and performs fantastic! I didn't think I could get so much tire in back, but a friend clued me into the correct backspacing, and it's available as a custom order on the American Racing TT2.

Will willwood brakes front and rear change the backspacing? I guess I will find out when I call American Racing?

Thank you for all the input. 

I like the idea of big wide rear rubber but will propbibly go with a bit less just to be sure I get no rubbing issues.


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## TriPower65 (Mar 18, 2014)

I am in the process of figuring out all of this on my '65. Great info in this thread.

Could you guys possibly post some pics of your cars so we can see what this all looks like on the ground? TIA.


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## Joe'sToy (Mar 9, 2012)

TriPower65 said:


> I am in the process of figuring out all of this on my '65. Great info in this thread.
> 
> Could you guys possibly post some pics of your cars so we can see what this all looks like on the ground? TIA.


I'll post pics once I have my coilovers installed. Kit arrived today, but won't get to the install till next week, as I'm already booked for the weekend.

Joe.


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## TriPower65 (Mar 18, 2014)

Perfect. Thanks.

Sent from my SM-G930V using Tapatalk


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## Joe'sToy (Mar 9, 2012)

Okay, so finished installing my new front and rear Coilover conversion this evening. I say it turned out pretty good, no lost or crushed fingers. Drove it for about an hour and will have to adjust the front drivers Coilover as I was getting a slight rub during full turn and going over some curbs. I have to say, the ride quality is great and the handling is vastly improved. I also like how the stance turned out, but like I said, a little more adjusting and it will be perfect.


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## Joe'sToy (Mar 9, 2012)

More pictures of install.


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## Joe'sToy (Mar 9, 2012)

Some pictures of the front install.


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## Joe'sToy (Mar 9, 2012)

Some pictures of the final look and stance. I'll get more from a different angle tomorrow, just ran out of time tonight.


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## cij911 (Oct 25, 2017)

Joe - Looks great!

Any chance you measured your coilover setup before installation (so I could use that as a starting point) ? I might choose to go slightly higher than you did or more of a rake, but very close to your look.

It would be interesting if folks have cornered balanced this platform and figured out what is best.

My setup should arrive in a bit (2 week + cycle time  ...) ....I can't wait to get to the suspension installed, but wished I had your garage / lift setup to make the job slightly less painful.

Thanks again for all of your help.

Chris


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## renorealtors (Apr 7, 2018)

Hi Joe and Chris,

I finally got the wheels from American Racing Yesterday. I am now picking tire sizes. The wheel size AR picked for the 65 GTO is 17x7 with 0 offset up front and 18x8 and 0 offset in the rear. I am wondering if that is "0" back spacing?? Can't be right. They look good and are not crazy wide. Any tire size you would recommend?

Thank you John


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## renorealtors (Apr 7, 2018)

One more pic


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## Joe'sToy (Mar 9, 2012)

renorealtors said:


> Hi Joe and Chris,
> 
> I finally got the wheels from American Racing Yesterday. I am now picking tire sizes. The wheel size AR picked for the 65 GTO is 17x7 with 0 offset up front and 18x8 and 0 offset in the rear. I am wondering if that is "0" back spacing?? Can't be right. They look good and are not crazy wide. Any tire size you would recommend?
> 
> Thank you John


Hi John,

The "0" offset is not back spacing, you'll need at least 4.75" in front and 5.00" for the rear, if you stay with the 17" and 18" rims. The offset is how far the face of the hub is either out or in towards the hub. Backspace is how far the outside edge of the rim sticks out from the hub face. Offset can be negative or positive. With "0" offset, the hub face will be in the exact middle of the rim. Hope that helps.


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## cij911 (Oct 25, 2017)

renorealtors said:


> Hi Joe and Chris,
> 
> I finally got the wheels from American Racing Yesterday. I am now picking tire sizes. The wheel size AR picked for the 65 GTO is 17x7 with 0 offset up front and 18x8 and 0 offset in the rear. I am wondering if that is "0" back spacing?? Can't be right. They look good and are not crazy wide. Any tire size you would recommend?
> 
> Thank you John


225 - 245/45 front

255 - 265/40 rear (I think the 275/40 would bulge too much on an 8" wheel and possible causing fitment issues)....

Attached are my wheels (245/45/17 front & 275/40/17 rear).


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## Joe'sToy (Mar 9, 2012)

cij911 said:


> Joe - Looks great!
> 
> Any chance you measured your coilover setup before installation (so I could use that as a starting point) ? I might choose to go slightly higher than you did or more of a rake, but very close to your look.
> 
> ...



Chris, before I did the Coilover's, I measured 27.5" from level ground to the middle bottom of my front wheel opening. Basically right in the middle of my wheel opening. The rear I measured 26.75" from the ground to the middle of the rear wheel well. After I did the Coilover's the front is now 26.25" and the rear is now 27.25". I did have the front lower but with me sitting in the car, it compressed about .75" so I adjusted the front up about another full inch. I'll have to see how much it compresses over the next couple of days, may have to do some more small tweaks to get it perfect. But I am very happy with the ride and handling so far. Attached is a before and after pic, from the side, which gives a better view.


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## renorealtors (Apr 7, 2018)

Hi Joe,

"The "0" offset is not back spacing, you'll need at least 4.75" in front and 5.00" for the rear, if you stay with the 17" and 18" rims."

So it looks like American Racing has sent me rims that will rub the fenders, the BS on the front is 4" and rear is 5"? If you were going to do 17" front and 18" on the rear you would go go the 17x7 -4.75"BS and 18x8 -5"BS or 18x9.5 5.25"BS?


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## renorealtors (Apr 7, 2018)

Excuse me the rims they sent are 17x7" with 4" BS and 18x8 with 4 1/2" BS


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## Joe'sToy (Mar 9, 2012)

renorealtors said:


> Hi Joe,
> 
> "The "0" offset is not back spacing, you'll need at least 4.75" in front and 5.00" for the rear, if you stay with the 17" and 18" rims."
> 
> So it looks like American Racing has sent me rims that will rub the fenders, the BS on the front is 4" and rear is 5"? If you were going to do 17" front and 18" on the rear you would go go the 17x7 -4.75"BS and 18x8 -5"BS or 18x9.5 5.25"BS?


They may still fit, depends on the tire size your using. With my setup, I went with 225x45x17's in the front on a 17x8.5 rim, offset is 0 mm and BS is 4.75" On the rear I have 275x40x17's, with an 17x9.5 rim. The offset on those is 0 mm and the BS is 5.00" There was no rubbing whatsoever, but now I just did coilovers front and rear, which dropped my GTO by a few inches, all the way round. So tire size will determine if your setup will rub, you may have to decrease the width of the tire, so they fit. Hopefully someone else will chime in and help.


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## cij911 (Oct 25, 2017)

Just installed my wheels and tires (245/45/17 front & 275/40/17 rear). The wheels are American Racing Torque Thrust II (polished) 17x8 (front) & 17x9.5 (rear). The tires are BFG GForce Sport C2. So far I like how the tires perform.

I will lower the front a bit when I install my new suspension, but plan on keeping the rear height as is. I am so happy they fit!


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## Joe'sToy (Mar 9, 2012)

cij911 said:


> Just installed my wheels and tires (245/45/17 front & 275/40/17 rear). I will lower the front a bit when I install my new suspension, but plan on keeping the rear height as is. I am so happy they fit!


They look great, you'll be happy when you get the coil overs done. I did a show last night in a small town north of me, about 90 Klm's each way and I have to say, the improved ride and handling was very nice.


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## renorealtors (Apr 7, 2018)

Hey Guys,

I am going to take off the calipers and rotors so the original ugly wheels will fit to make it roll. After paint I will check it out with the body on. I think it will save a lot of work not to mention cleaning if the painter hits the new wheels!


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## renorealtors (Apr 7, 2018)

Update 11/29/18 Motor is about to go on the dyno. Did all Butler stuff with a local machine shop building and dynoing it. How exciting! Stroker bottom end, edlebrock heads with some custom porting, cal cam from butler, big oil pan, roller everything,and more. The next step will be to get the motor/trany installed and send the frame back to the pint shop.


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## renorealtors (Apr 7, 2018)

Update 12/25/18 Just got the motor back from the machine shop after dyno work. Does anyone have a PDF or link for a 1965 GTO wiring harness?? Also a pic of a Street Tracker I just finished.


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## cij911 (Oct 25, 2017)

renorealtors said:


> Update 12/25/18 Just got the motor back from the machine shop after dyno work. Does anyone have a PDF or link for a 1965 GTO wiring harness?? Also a pic of a Street Tracker I just finished.


Nice dyno graph! Can you provide some details on the motor (I see you have aluminum heads)? (Attached are diagrams for a 66. I will upload my paper diagram in a few minutes.) Thanks


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## renorealtors (Apr 7, 2018)

Hi 911 Go to the new thread for this info. " 65 GTO Build"


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## renorealtors (Apr 7, 2018)

Finally seeing some progress!! The painter said I should have the car back by the end of the month!!


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