Conversion from .64 to .82 for T600

[Mike Bartlett]

So, I was one of the bone heads who ordered the .64 with 3:31 gears. 1800 rpm' at 70 mph doesn't cut it with my motor. Pings at the slightest hill when in 5th.

Has anyone converted there's from .64 to .82? How do you like it? Do it yourself or have a shop do it? How much did it cost?

Thanks.....

Mike

[wtm442]

I do not know about changing 5th gear, but if you are pinging under slight load, back off the advance or use higher octane gas.

[Rick Parker]

Shift to 4th???

[wtm442]

That low 5th gear is useless with 3:31 rear gears. I have same tranny but 3:73 rear gears. Check out price of new rear gears ... car will go faster in lower gears, or spin the tires easier

Either way will be expensive when compared to Rick's comment.

[Jimi G]

Originally Posted by Mike Bartlett

So, I was one of the bone heads who ordered the .64 with 3:31 gears. 1800 rpm' at 70 mph doesn't cut it with my motor. Pings at the slightest hill when in 5th.

Has anyone converted there's from .64 to .82? How do you like it? Do it yourself or have a shop do it? How much did it cost?

Thanks.....

Mike

Mike,

The swap can be alittle difficult if you have never been inside of a standard transmission before, as for the parts you can expect to pay somewhere around $500.00. Changing the rear gears to 3.73 will be the cheapest and easiest way to help raise your rpms in 5th. If you can give me some specifics on your car I can see what your rpms will change to with the rear gear change or the 5th gear change in the transmission. I will need to know your rear tire size and I can tell you the difference you will see. jimig@standardtransmission.com

[SPF1061]

Mike -
What engine are you running? As pointed out , back off the timing if you're pinging under a little load at 1800 rpm. That's bad news.
As to gearing. Dropping the rear to 3:73 may be the cheapest change - but not the best solution. 1st gear will become absolutely useless for anything other than setting the rear tires on fire. I changed my 427R SPF from a .64 od / 3:73 to a .82 od / 3:23. This was one of the best mods I have done to the car. 100% improvement in drivability. First gear and fifth gear both turn into usable performance gears. If you have a larger engine with some low end torque, I promise you, you will love this combination. If you have a high revving peaky smaller displacement engine this gearing may not work as well. Good luck with your decision and ahve fun!
-Steve

[CobraEd]

If you have a vacume advance, that is responsible for your part throttle advance. Get an adjustable vacume advance, and dial it in for latter advance. Then you still have the same full throttle power from your static/mechanical advance with none of the pinging at part throttle.

[STEVE POTTS]

Why cant somebody make a 5th gear ratio somewhere in the 0.75 for the tko600's. Give the market what it wants.

[Poolw]

Get a 6 speed and drive it 5th.

[Coloradocobra]

Given the popularity of the TKO600 right now, you might want to try to sell your old one locally and buy new with the correct ratio. The total cost of replacement might be equal to or less than the $500 difference and you won't have to open it up. Do you have an active Craigslist in your area?

Just a thought...

[rblong]

Originally Posted by SPF1061

Mike -
What engine are you running? As pointed out , back off the timing if you're pinging under a little load at 1800 rpm. That's bad news.
As to gearing. Dropping the rear to 3:73 may be the cheapest change - but not the best solution. 1st gear will become absolutely useless for anything other than setting the rear tires on fire. I changed my 427R SPF from a .64 od / 3:73 to a .82 od / 3:23. This was one of the best mods I have done to the car. 100% improvement in drivability. First gear and fifth gear both turn into usable performance gears. If you have a larger engine with some low end torque, I promise you, you will love this combination. If you have a high revving peaky smaller displacement engine this gearing may not work as well. Good luck with your decision and ahve fun!
-Steve

Dito - went to .82 trans with 3.25 - perfect for a high HP/TQ motor

[RodKnock]

Mike, did you ever swap 5th gears or did you sell the old tranny and get a new one? If you did swap 5th gears, then what did you pay someone for the labor to do so?

[Mike Bartlett]

RodKnock,

I spoke with Jim at Standard Transmissions and he said it would be pretty costly to do the swap. The entire tranny needs to be gutted to get to the 5th gear. Also a fair amount of parts are needed as well. Jim statedIt probably makes more sense to buy another tranny.


Mike

[4pipes]

Mike, I have the same transmission with my 482. I like cruising along a 1700 rpm in 5th gear at 70mph. You can actually talk to a passenger or think without a lot of noise (except for wind).

[Mike Bartlett]

Dave,

I do like the 1700-1800 crusing at 70mph but my motor doesn't. It will ping at the slightest incline. Then downshifting to 4th at 70 I'm at 3200 rpms. Not a good alternative either. I am about done rebuilding my motor maybe it will be better? If not I guess at some point I'll get the correct OD with either a new trans or new th gear.

Mike

[RodKnock]

Thanks, Mike. I kinda thought that would be the answer. My trusty old speadsheet says that with a 3.31 final drive ratio, the RPM's at 70 mph would be roughly 1,900 rpms with the 0.64 and 2,450 rpm with the 0.82. From personal experience, I think 1,900 is low and the CHP may not like 2,000-2,200 rpm.

[jwd]

Originally Posted by rblong

Dito - went to .82 trans with 3.25 - perfect for a high HP/TQ motor

This combo gives you a usable 1st gear AND 5th gear. I drove every combination of trans. and rear gears before deciding on this one.