I would recommend the 600 for sure. The 500 is just geared too low for a big block and I would drive it first before making any gear ratio changes. The .64 o/d might be a bit too much overdrive for a 3.36 but you won't know until you drive it. 2100 rpms will be about 75 mph.

Ratios: 2.87 1.89 1.28 1.00 .64 o/d

Jeff

 

Thanks Jeff, something to think about for sure... cost vs benefit, etc

 

I installed a Kiesler RS400 in my '69 350/350, manual, 3.70 gears. Their product and service was outstanding. I did a body off resto on this car and the 5spd was the best improvement I made! I drive the car 3X more often because I can now cruise at 75-80 mph easily.

 

I've had a Richmond 5 speed with 1:1 5th with a 435. The 3.27 first and a 3.08 make for a good set-up in first gear, but there is no comparison when it comes to a 5th gear to 5th gear head-to-head vs. a TKO600. With the Richmond 5, you are at a 3.08 ratio at cruise, with my 3.73 rear and the TKO600 (unbelievable in 1st), in 0.64 OD 5th, the OD ratio is effectively a 2.39. With my 468, I could be happy with a 3:55 rear really. Even so, I'm doing 2320 at 75mph with short 50 series tires. Running a 27" rear tire would drop the rpm by 100 at 75. Add the fact that the TKO600 is stronger and I would not give the Richmond 5 non-OD another thought. It's the OD gear that transforms the car from a noisy monster into something much quieter and refined, so to speak, if that word can be applied to an old-school 500 HP Vette. I have a 540 now with Max-Flows in the side-pipes and it's not that bad at cruise.

 

If I were to do it again I'd get the Richmond 6 speed. It would be nice to have an extra gear when I'm cruising at 85.

 

If I had the tko 600 to do again it would have went with the better sincros and the .82

Your higher rpm doesn't deal with low rpm OD driving. I had 4.11 and the .64 and the 4-5 jump was a lot, but 4.11 made the od totally usable. The first 4 were really closed up and it made for driving around a road race track in 3-4 and 5th on the main straight.

I then went to 3.55 to use the first 4 gears, but 5th sucks. It is more like a 80+ mph

 

I bought two TKO600's from Keisler (spelling) before they went bankrupt. One for the 68 and one for the 70.

Background: My original plans were to use a Richmond 5 speed in the 70 and a 3.08:1 differential. I originally had a Doug Nash 5 speed in a 69 with a clone L88 engine and a 3.08:1 differential. Worked out fine,..Doug Nash transmissions were bought out by Richmond..so I thought I't be like old times using the Richmond 5 speed with a 3.08:1 differential in the 70 BB. The 70 is slated for a horsey 496/502 engine. Just as the 70 diff was to be built up with a Tom's super 10 bolt rear end, I discovered on the internet that the Richmond would not tolerate the ft-lb ratings of high performance BB's. I read that when Richmond began reproducing the Doug Nash 5 speed, they lowered the torque ratings of the trannie to reduce costs. So I made a quick call to my diff rebuilder and he had not started my job. I made a decision to buy a TKO600 with it's much higher foot-lb torque ratings and so with the TKO600 I had to have the rear end built up with a 3.73:1 rear end. (Diff rebuilder gave me a trade-in allowance on my no longer needed 3.08:1, the rear end gears were from Tom's) With the Richmond, you really don't want a rear end diff ratio greater than 3.08:1 and with the TKO600 you don't want a rear end gear ratio less than 3.73:1.

After restoring my 68, and out on the road for the first time in almost 30 years, I was dismayed that it was running 3000 rpm at 70 mph. (ZZ4 engine). The high engine speed drove me nuts. So I purchased another TKO600! Overkill since the torque rating of the TKO600 is much more than the ZZ4 will produce. Still a very nice smooth and easy shifting transmission, shifter has a short throw and ...2000 rpm at 70 mph. I'm still using a stock gear shifter handle so no one can tell it's a 5 speed. I had the tranny crossmember on the 68 converted to being removeable. This makes replacing the trannie soooo much more easier. I had this done by J&D Corvette (Bellflower, Ca) they cut the crossmember about 1 1/2 feet away.on both sides, from the transmission mount, and welded in flange plates to mate the crossmember back into one piece.

I think the TKO600 was an original trannie on the early Vipers...don't know for sure.

 

No need to change the clutch linkage. My ZZ4 equipped TKO600 trannie has a McLeod dual friction clutch (single disk) and it's very easy to shift. My 70 has a McLoed dual disk clutch..I've yet to drive this car. Both cars are using the stock aluminum GM bellhousings. The stock GM bellhousings will install without bellhousing alignment procedures required by repro bellhousings.

 

As an alternative to the stock GM housing, I went with this QuickTime unit and it did not need alignment as well. It is not a stamped housing like Lakewood's old versions. This particular one is not SFI certified because it doesn't use a engine block plate. I mainly got it for my own personal protection for my feet & legs. Very good quality.

http://lakewoodindustries.com/drivet...ment-bell.html

One note. If you are not using a mini-starter, the starter hole has to be opened up on the passenger side to accept the starter nose.

 

Thanks all... I'm going to seek some advice of original M20 vs 5 speed, etc in a separate thread

 

You can't make a general statement like that and have it be true for everyone, it all depends on the engine's torque capability. A friend runs a 468 with a TKO600 with 0.64 OD and a 3.08 rear. The engine makes 500 RWT and cruises with no problems. Put that combo on a cammed-up small block and it might not work out. Not everyone wants the first gear x rear ratio (10.7) to be that high either. You need to consider small block versus big block. And cruiser versus road racer with the OD gear (0.64 or 0.80). For me, a 3.55 would have been fine.

 

if you have the money the t 56 is the only way to go.

 

I have a '71 350/270 4-speed that I'm considering doing a 5-speed conversion.

I thought that it's desirable to have the first gear x rear ratio be as close to '10' as possible, no?

I'm not doing any racing. What 5-speed trans (TKO500 or TKO600) and rear end ratio would you recommend for my '71?

Thanks