# Tremec TKO 600 question ?



## bondobill (Oct 24, 2011)

Hi all

Brents looking at swapping out the M20 for a 5 speed in his 68 goat.

With the new 464 stroker another gear would be nice for freeway cruising.
Car has 355 rear.
We need to pull the M20 this winter, it's jumping out of gear on decel, if you lay your hand on the shifter it stays in gear. We got through the summer with it but with winter coming we are going to need to pull it
We wanted to put in a 5 speed sooner or later and kinda figure now might be the time for the swap

We got a quote from SST for PerfectFit kit TKO 600. Supposed to come with everything required for the swap. Comes with a new driveline and you retain the original crossmember.
It does say some mods are needed to the tunnel, anyone know how much modifying is needed.
We done some searching on here and on PY and for the most part folks that have installed the TKO 5 speeds are happy with them. 

Has anyone on here dealt with Silver Sport Transmission. They got back to us really quick with the quote via e-mail and by mail. The quote we got is good for 30 days.

Thanks

Bill


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## PontiacJim (Dec 29, 2012)

You will most likely have to change the rear gear as 3.55's may be too low to use the overdrive at cruising speeds. The TKO has 2 different OD ratio's for 5th gear. Decide which you want, then find one of the online calculators for tire size(typically 26" in height for stock type tires), rear gear ration, MPH, RPM, and final gear ration of transmission. You don't want to be turning 1,600 RPM @ 70MPH and have a theoretical top end of 200MPH. You will be lugging the engine -bad thing.

Modifying the trans tunnel means cutting the floor up. The TKO is way bigger than the Muncie. I think if you search you will find pictures that shows this modification. Found a Chevelle forum that shows what you have to do and cut.

The TKO will not go high rpm's, typically over 6,000, unless you have the trans modified should you have a high revving combo. With a typical Pontiac engine, this should not be a problem. They may have corrected this on their newest versions, but I'm not sure.

There are several companies that offer the full conversion "kit". Shop around & compare before buying.


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## Nightshade 68 HO (Mar 11, 2014)

I have this trans in my monte and Jim is right, it is a big trans and you do have to cut and raise the tunnel about an inch. I run a 3.42 gear with the 600 and have zero problems in 5th gear and cruise at 70 at about 2,000 (mind you the tachs on montes are notoriously inaccurate, but I have never had a lugging problem. The old trans like mine have a balky 2nd to 3rd shift though.....had mine since 2006. I believe the TKO 600 5th ratio from memory is .62


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## PontiacJim (Dec 29, 2012)

Nightshade 68 HO said:


> I have this trans in my monte and Jim is right, it is a big trans and you do have to cut and raise the tunnel about an inch. I run a 3.42 gear with the 600 and have zero problems in 5th gear and cruise at 70 at about 2,000 (mind you the tachs on montes are notoriously inaccurate, but I have never had a lugging problem. The old trans like mine have a balky 2nd to 3rd shift though.....had mine since 2006. I believe the TKO 600 5th ratio from memory is .62


Thanks for the input on the gear ratio/rpm's as I don't have any hands-on experience. I don't know if your engine is stock? or modified? I would think with a bigger cam that 2,000 RPM might be a little balky, at least that was my thinking if you had a cam power range that typically runs from 2,500 RPM and on up. 

Also, at that MPH/RPM, it would seem to me that you could not use 5th gear until you hit close to 70MPH whereas if you had 3.73, 3.90, or even 4.11 gearing you would get the advantage of extreme acceleration from these ratio's and then utilize the 5th gear OD. I suppose it really boils down to how you plan on driving the car and if you do mostly city driving/cruising or highway running. I have the TKO600 going into my project which I plan on using 3.90 gears with tall tires, but I want performance/acceleration around town/cruising......and shutting down LS Chevy powered rides.:thumbsup:


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## ppurfield001 (Jan 21, 2008)

PontiacJim said:


> Thanks for the input on the gear ratio/rpm's as I don't have any hands-on experience. I don't know if your engine is stock? or modified? I would think with a bigger cam that 2,000 RPM might be a little balky, at least that was my thinking if you had a cam power range that typically runs from 2,500 RPM and on up.
> 
> Also, at that MPH/RPM, it would seem to me that you could not use 5th gear until you hit close to 70MPH whereas if you had 3.73, 3.90, or even 4.11 gearing you would get the advantage of extreme acceleration from these ratio's and then utilize the 5th gear OD. I suppose it really boils down to how you plan on driving the car and if you do mostly city driving/cruising or highway running. I have the TKO600 going into my project which I plan on using 3.90 gears with tall tires, but I want performance/acceleration around town/cruising......and shutting down LS Chevy powered rides.:thumbsup:



I have a 1967 GTO with a 400ci/335hp motor and 3.55 posi rear end. I changed out from the stock 4-speed stick from GM to a Keistler 5-speed stick with fifth gear as overdrive. The service rep. told me that once I hit fifth, the tachometer should read no more than 1,800 RPMs. Darned if he wasn't right. Had to move the location of the shifter a few inches and had to purchase a custom-fit drive shaft from Keistler. I love the five-speed and would recommend Keistler to anyone who asks. They're in Tennessee if I recall. Good luck.


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## ALKYGTO (Mar 29, 2010)

Floor mods are needed as said I had to raise the center of my trans tunnel about 1 inch. Once you cover it with carpet it is imperceptible.

I purchased my TKO from Keisler but I don't think they are in business anymore. 

My overdrive ratio is .82 and with 29" tall tires and 4:11 gears 75 mph is about 2300 rpm, perfect for my car. If I recall they do have two OD ratios available. I felt the .62 was too high for my car. I calculated it out once and I believe it worked out the same as if I had a 1:1 4th gear and a 2:93 final drive ratio.

If anyone is concerned about strength I'm pushing 800+ hp to the wheels in a 3600 lb car with a 12.5" inch tire and it has let out nary a whimper. Shifting is a little notchy but I also spin it over 7000 rpm when I shift.


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## bondobill (Oct 24, 2011)

Thanks guys for the in put 
The info SST sent us shows 5th gear to be .64.
With a 355 rear their graph shows 2200 rpms at 75 mph, but I don't think it takes in rear tire height. 
We are running 27.1" tall rear tires, I think stock was 26.4" 
With a .82 5th gear it drops to 59 mph at 2200 rpms, there again that is according to their graph

This is getting confusing !!

Bill


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## PontiacJim (Dec 29, 2012)

bondobill said:


> Thanks guys for the in put
> The info SST sent us shows 5th gear to be .64.
> With a 355 rear their graph shows 2200 rpms at 75 mph, but I don't think it takes in rear tire height.
> We are running 27.1" tall rear tires, I think stock was 26.4"
> ...


With your specs, .82 OD at 70 MPH you will be turning 2536 RPM's

Using the .62 5th gear OD, 70 MPH will be 1917RPM's 

So your 2200 RPM's @ 75 MPH is for the .62 ratio 5th gear and your 5th gear -59MPH @ 2200 RPM's is correct for the .82 OD. 
If you went with the .62 OD, it would be 59MPH @1610 RPM's.

Each OD 5th gear ratio gives different RPM's/MPH based on rear axle ratio and tire height.


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## Nightshade 68 HO (Mar 11, 2014)

Jim,

I have a ZZ-383 Stroker motor in my Monte Carlo SS. 425 Horse engine. I have a single plane intake and a 750 Double pumper. I can put my car in 5th at 50 mph and it does not lug with a 3.42 gear. I get approximately 20 MPGs to 23 MPGs with this combo. I just calculated that on a return trip from Carlise, PA and the car used 7.8 gallons for about 195 miles. I could not believe my eyes


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## khinton (Jun 22, 2008)

*Tremic tko*

I have a 55 chev with a 350 cu in 355 hp ZZ4 crate motor. I have 6000 miles since the motor and install of the TKO with .64 over drive ratio. The rear end ratio is 3.70. The car runs 2100 at 70mph. I'm happy, don't feel it lugs at all at lets say 50mph in 5th. (would shift back to 4th to pass) I actually would like a little taller rear end as it would make driving around town a little easier. I'm not into draging my car. Just want it to drive like a modern day stick would. Just sayin. :wink2:


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## bondobill (Oct 24, 2011)

Thanks all :thumbsup:

Our 464 stroker seems to be the happiest above 2200 rpms 

Seeing's how we aren't going to get on the Interstate much.

Maybe .82 OD would be our best option.

Bill


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## joesweeting (May 8, 2011)

Bill,

I have a TKO 500 in my 69 GTO with a 3.55 rear end. It was behind a 461 before I started my LS engine swap. I chose the TKO 500 instead of the TKO 600 because it has a 1st gear of 3.27. The TKO 600 has a 1st gear of 2.87. However, it has 2 different choices for final gear ratio, either .82 or 64. I did have to trim the floor pan a little, but mine was not made by Kiesler. Also, during the frame off restoration, most of the body bushings were bad. If the we're good I might of not had to trim it at all. 

Joe


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## bondobill (Oct 24, 2011)

Brent ordered a Tremec 5spd this week Weds.
He received a call from Silver Sport...formerly Kiesler.... yesterday Friday 16th that the perfect fit kit was shipping.
We should see it by next week Friday.

We decided on the .82 od.

Thanks guys 
Bill


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## alanjnc (Jun 5, 2015)

so I am insisting on putting a 5 or 6 speed in my '69 Judge....as it is numbers matching and pretty original (other than sitting in the garden of a guy's house since 1979, I am loathe to "cut it up". Is there no tremec or legend trans which will go in without cutting the floor pan?
Any advice or experience (preferred) is welcome!!
Alan


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## 65gto (Aug 2, 2013)

I've been looking at this McLeod 5 speed.  Still trying to get more info 

http://www.summitracing.com/parts/m...GdDPwglPatK2vzHGunlcqpCR8yh7e9i197RoCN2zw_wcB


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## knucklehead12 (Nov 14, 2013)

If anyone has any information on the McLeod Muscle 5 please chime in. I am trying to decide between the Tremec and the McLeod.


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