Bought a TKO 600 for my 68.

I just bought a TKO 600 Friday. I bought it from "Chris" at Keisler. I asked and Chris said the TKO 600 needed a different pilot bearing than the Muncie.

I wasn't happy to hear that. When I installed a ZZ4 into my 68, I installed a new roller pilot bearing. It was difficult to get in. I used an extension (long) socket about the same OD as the pilot bearing I was installing and pounded it in with a mallet. It's going to be a SOB to remove I afraid. Maybe Chris thought I had a stock bronze bearing, and maybe the TKO needs a roller, etc, so maybe I'll be ok after all.

I wanted to buy a TKO 500, but it turns out that the gear ratios of the TKO 600 most perfectly match the stock M-20 Muncie. The 600 is a much stronger tranny (600 ft-lbs), but it's more expensive. The tranny and the complete kit, including a new driveshaft, came to $3499. The TKO 500 has a much lower (numerically higher) first gear, so the TKO 500 would red line me in first gear too quickly. That's why the TKO 600 was recommended and when you look at the gear ratios (below), you can see that the 600 is a natural.

Muncie M-20: 2.52, 1.88, 1.46, 1.00
TKO 600:...... 2.87, 1.89. 1.28. 1.00, 0.64

Keisler quotes a 2 or 3 week shipping delay. They said they have to remove the tail piece and machine it to fit the Vette. Since they have the tail piece off, they also apparently disassemble the tranny and re-assemble it. They said they've had problems with Tremac quality control, so they verify that everything is to-spec before shipping.
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With my Muncie I do 3000 rpm at 70 mph. That really sucks the gasoline down.
Now I'm going to be looking at 1920 rpm at 70 mph. Of course, considering the amount I drive the car, I'll never rally make up the $3499. But this will help my 68 survive in a world of high gasoline prices. It's 42 years old and I hope it's still drivable 42 years from now. With the replacement of the tranny, every moving mechanical part in the drive train, with the exception of the tachometer, will be new. My 68 may be drivable 42 years from now, but I don't think I'll be driving the car unless I live to 112 years old.

i've received my TKO-600 tranny and all the bits and pieces for the install. About that pilot bearing............

The pilot bearing in the TKO-600 kit visually looks like the same roller bearing pilot busing I pounded into my ZZ4. I took the TKO-600 pilot bearing and slide it over the input shaft of the TKO-600. It had a little bit of wiggle room. I then took the same TKO-supplied pilot bearing and slide it over a spare Muncie input shaft that I have. It had the same amount of wiggle play. It felt the same when I installed it on the TKO-600 as when I did when I installed it on the Muncie input shaft. I really don't think I need to replace the roller pilot bearing now installed in the ZZ4 when I install the the TKO-600. The ZZ4 probably has less than 300 miles on it.

Definitely want to see install progress pics!

I copied your posts in the pilot bushing thread into this thread. I'm sure people will be interested to see you progress on this.

Today I drove my 68 back home with the TKO600 5 speed manual tranny installed. The install was done by J&D Corvettes in Bellflower, California. They also mod'ed my tranny crossmember to be removable. It was a very professional conversion. A heartfelt thanks to Noe, the service manager, and Froylan, the technician who did the hands on work.

My opinion is that converting a manual transmission crossmember to being removable is a must. Placing in a bigger transmission like a TKO 600 or a Richmond 5 speed, although it can be done with a stock welded in crossmember...is about like pulling out fingernails. Convert the crossmember to being removable.

After driving the stock Muncie and stock shifter, the TKO shifter was immediately different. For the "H" pattern shift for 1-2--3-4. the TKO shifter pattern was a lot "smaller." The shift distance from 1 to 2 and 3 to 4 was much less than the Muncie stock shifter. Also for the "H" pattern for 1-2 and 3-4, the horizontal distance between the 1-2 and 3-4 planes is much smaller. Of course, for fifth gear, it's to the upper far right outside of the H pattern and reverse is straight down.

With my Muncie, in 4th gear at 70 mph my engine was turning 3000 rpm. At this rpm level it's easy to imagine a lot of engine wear and stress and also, for sure, very bad fuel economy. Also, the high engine rpm just was emotionally very annoying.

The TKO600 has gear ratios that are very much like the stock Muncie for gears 1 through 4. For fifth gear, the TKO 600 has a 0.64 overdrive. Hence my approximate 3000 rpm to 2000 rpm drop at 70 mph.

There is also the TKO500. It also has a 0.64 overdrive in fifth gear, but its first gear is very numerically higher than the Muncie. With the TKO500, first gear may not be practical since you can red line very quickly from a standing start.

For a Muncie replacement, the TKO 600 is the way to go especially since the four lower gears are almost the same as a Muncie. However, the TKO 600 is far more (($1000?) more expensive than the TKO 500. The TKO 600 can withstand 650 foot-pounds of torque, the TKO 500 has a much less foot-pound of torque rating (500?).

I bought my TKO600 from Keisler. They are in Tennessee and their customer relations are great. (My 68 install is a little bit different than the 69 and up install, so this caused some conversation. Everything worked out fine.)