# 66 gto ?



## noluck (Aug 13, 2008)

hello, just found this forum and hoping someone can help with a few ?. im working on a 66 gto 389 tripower, does anyone know the curb weight, its a 389 tripower/ 4 spd, no air
also the vibration dampener is kind of odd, its more or less just a hub that the pulley bolts to, no rubber core and outer ring like a chevy? is this right?its also cracked near the keyway , are any replacements available? last ?, someone put a 58 chevy rearend in it and were trying to find a 66 rear to go in it, does anyone know what will directly interchange(chevy, buick olds ect) and will gears from a chevy work in the pontiac rear. any info is really appreciated
thanks


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## geeteeohguy (Feb 2, 2008)

Curb weight is around 3600 pounds for a hardtop. The balancer should have rubber visible between the two pieces. It may be painted. It doesn't matter, though, 'cuz it's cracked. Unusable. New ones are available through the vendors (Year One, Ames, ETC.). Get a new one. Any 10 or 12 bolt rear from any GM A-Body from 1964 thru 1972 will work. By A body, I mean Tempest, GTO, Lemans, Chevelle, Skylark, Cutlass, etc. The 1966 and later units are one inch wider than the '64 and '65 units. You can run a slightly wider rim with the earlier units. Chevy gears? What for? Use the gears the rear came with, or spend the big bucks and get a posi with new gears. Hope this helps.
Jeff


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## Eric Animal (Oct 28, 2007)

No Luck, Welcome. You should have no problem finding the proper fitting 10 bolt rear for your GTO. Consider going with a 3.55 rear gear, as this is a good all around set up for your car. :cheers EA


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## rick3452 (Jun 14, 2008)

No luck, I just took my 355's out of my 10 bolt "66" two weeks ago and put in 323's, PM me if interested in buying.
Good luck.....Rick


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## Rukee (Feb 8, 2007)

How do you like the 3.23s?


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## noluck (Aug 13, 2008)

thanks a lot for the replys, you all helped a lot


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## rick3452 (Jun 14, 2008)

Rukee said:


> How do you like the 3.23s?


Hi Rukee,
Not a huge change, I still need to change the speedo gear, but I do have peace of mind having all new seals and bearings.
Thanks for asking....Rick


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## Eric Animal (Oct 28, 2007)

Mine has a T400 with 2.98"s...dead off the line, but from 50 mph up, really flies...:cheers


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## geeteeohguy (Feb 2, 2008)

Eric, are you sure you don't have 2.93'S? That's what my buddie's '67 had (it was an A/C car) and it would kick down into passing gear at 85mph!! We'd listen to Deep Purple's "Highway Star" and go out looking for prey........


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## Eric Animal (Oct 28, 2007)

Yep that's what i meant...2.93's....a friend of mine had a 66, maroon, named "highway star".........I am thinking of a set of 3.55's . I need a little more gear so I can bake some of the excess meat off the rear tires :willy: arty: Eric


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## geeteeohguy (Feb 2, 2008)

Go with 3:23's or 3:36's. That way, you can use the same carrier. 3:55's, in my opinion, are a little too short legged for sustained hiway speeds and $4 gas. My '67 has 3:36 gears, and at about 70mph, it feels like it needs to upshift into the next (non-existant 4th) gear. Accelleration off the line is good, though. Try driving someones goat that has 3:55's and see what you think.....
Jeff


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## Rukee (Feb 8, 2007)

I have 3.55s with a 4-speed and some tall 15" tires on the back and love them. I do about 2800rpm @ 65mph and have pleanty of power to roast`em most any time I want.


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## geeteeohguy (Feb 2, 2008)

How often is THAT?


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## Rukee (Feb 8, 2007)

Most everyday.


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## Eric Animal (Oct 28, 2007)

I was also thinking of the 4 speed auto conversion.....much lower 1st gear ( for broiling, or frying tires) and OD to see if I can get the old goat to float on the open road........:willy: :cheers Thanks for the input fellas.EA


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## Eric Animal (Oct 28, 2007)

Rukee even managed to bake his rear/carrier unit....thats what I call dedication :cheers


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## geeteeohguy (Feb 2, 2008)

Sounds like you guys like to roast your meats and fry your tires. Me, I like to boil my hides. Yeah, I thought about an OD 4 speed auto in the '67 also, or a GearVendors OD unit. Thing is, I don't drive the car enough these days to benefit. The 200R and 700R4 can be made to work well, but then it's not original, blah blah. I wish they had a lockup converter for the TH400. That would make a huge difference. I think Rukee's got the right idea: run intermediate gears and adjust the tire size/height to match....I think the stock tires are about 25-26 inches tall. Sounds like we need to come up with some tire cooking recipes: Bake, Broil, Fry, Smoke, Boil----what's your flavor?
Jeff


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## Eric Animal (Oct 28, 2007)

BF Goodrich Flambeaux:willy: recipe to follow...too tired to type right now...E


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## Scott Gelande (Oct 3, 2008)

I just bought 323's for my tempest. Gevos rears and gears had two sets. I also found anothe guy who had a set. PM me if you need info.


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## auburnconsulting (Nov 3, 2008)

silly questions what rear end came in 64-67 gto's 10 bolt? 12 bolt?


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## 05GTO (Oct 6, 2004)

auburnconsulting said:


> silly questions what rear end came in 64-67 gto's 10 bolt? 12 bolt?


There were 18-20 options for rear ends each year for the 1st generation GTO (64-67), Type-C 12 bolt rear ends were not available for the GTO until 70.

Pontiac Rear Ends


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## auburnconsulting (Nov 3, 2008)

it appears my gto was a hot rod then. i'll pull the cover and check the ratio. i also have the 670 heads and i know they did not come out till 1967 and my engine and car was built in 1965.


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