TKO 500/600 question

[Jiggs]

I am new to posting on this site, but I think I am in the right place for the answer I am looking for.

Are these the same tranny, just different gear ratios, or are they totally different on the inside. Is it the ratios that specify torque rating? The reason I ask is I like the gear ratios of the 500 better. They will wake up the 3.08 gears/27" tire in my car. I think I need the 600 because of the torque that my engine produces. The car is a 67 LeMans with a 455.

Are the torque ratings of these units measured with no slip of the tires. (A lot of twisting going back to the engine) I will never drag race my car, so on the street there is always slip.

Would I be safe with a TKO-500 on the street, with over 500ft/lbs torque? OR would I be smarter to go with the 600 and a new set of gears for the rear and not worry?

The multiplication of first gear and rear gear gets me to 10.07 with the 500 and 3.08's. I would need to get 3.42's to get 9.82 with the 600.

Thanks, Tyler

[SDMAN]

Either one should be fine. If it were me, I would use the TKO-600 with a 3.90 rear gear. Thats what I used in the last version of my 70 GTO (with a 455 SD motor) and it worked pretty good. There is a good chance you will need to mod the top of the trans tunnel to get the trans in.

[gearbanger]

I don't think you will be able to use those 3.08s with the .64 overdrive. I have 3.73s and my car only turns about 2000 at 80 on the interstate. If I was dead set on keeping the 3.08s, I would use the 600 with the .82 overdrive.

[GMJim]

Jiggs
The TKO 600 .64 would be a little tall for 3.08's. With 3.08's I would look at the 600 Road race version with a .82 OD. You can use our RPM calculator at http://www.classicchevy5speed.com/RPM-Calculator.aspx to check out the different ratios.
Hope this helps
Jim

[Pontiac Chris]

Jim, I think your choice of the TKO 500 and 3.08's is perfect, it it will put your 27" tall tired LeMans at 2100rpm at 80mph. I am planning this exact same setup for my 68 Firebird which currently has a 2.41 rear gear and a Richmond 5 speed (no overdrive) with a 26" tall tire. I am doing 2550 rpm at 80 and this is too much rpm for my .630 lift, 325cfm headed little 400 Pontiac.

I know your 455 has enough torque to pull your car and accelerate it in 5th from 2100rpm at 80mph.

I have a 92 5.0 mustang with 3.08 and about the same gear ratio's as the TKO 500 and its perfect.

Any rear end gear steeper than 3.08 with a first gear that steep will be unuseable, you'll have moved 5 feet and be reaching for 2nd. Don't forget all these other guys with Chevys and Fords that have big cams and good breathing heads don't have anywhere near the torque of your 455 at low rpms thats why they need the high rpms on the freeway just to maintain 80mph.

I don't have that many miles on my new motor yet, but so far my 450 ft lb rated Richmond is holding up.

My question is the same as yours is the TKO 500 strong enough for a street car with occasional track use or do we need the TKO 600?

Chris.

[69Pony]

I don't think you will be able to use those 3.08s with the .64 overdrive. I have 3.73s and my car only turns about 2000 at 80 on the interstate. If I was dead set on keeping the 3.08s, I would use the 600 with the .82 overdrive.

Totally agree. I run the TKO 600 with .64 5th and 3.90 rear gears and I wish I had selected the .82 version instead. If you get the .62 with 3.08's you'll never put it into 5th gear south of 70mph without lugging along and sub 2k rpms.

[Pontiac Chris]

Quote:
Originally Posted by gearbanger
I don't think you will be able to use those 3.08s with the .64 overdrive. I have 3.73s and my car only turns about 2000 at 80 on the interstate. If I was dead set on keeping the 3.08s, I would use the 600 with the .82 overdrive.

Totally agree. I run the TKO 600 with .64 5th and 3.90 rear gears and I wish I had selected the .82 version instead. If you get the .62 with 3.08's you'll never put it into 5th gear south of 70mph without lugging along and sub 2k rpms.

69 Pony, GMJim and GearBanger, you guys are forgetting Tyler has a 455 Pontiac which has tons of low end torque! It can pull you're house down below 2000rpm!

Tyler the 3.08's will be perfect with the TKO 500, if you use the TKO 600 I would recommend a 3.23 rear end gear. It'll give you close to the same 1st gear ratio and close to the same final drive ratio as the 500 w/3.08's.

I may go with the TKO 600 and the 3.23 gear for peace of mind when abusing it as I gotta be close to the torque capacity of the 500.

Chris.

[osdmike]

I used to have a TREMEC TR3550, 3.27 first gear, .68 fifth gear.(same as TKO500)
Tires were 26.6" dia.
2.75 !!! in the rear.
"Starting line ratio" was 8,99.

That was tough job for the clutch.

If You choose the TKO 600 with the 3.08 ,You will end up with "Starting line ratio" :8,83!, since both .64 and .82 version has 2,87 first gear.

I would go TKO500 with the 3.08 gear.(If You want to keep it)
Or TKO600 with 3.25 - up.

Now I have TKO600 (.64) and 3,50 in the rear.(st.line ratio 10,04)
Much more fun to drive!