[rcweingart]

For what it's worth, Dennis Olthoff - who many think is the guru of the SPF Coupe, favors the TKO 600 5 speed with the 0.8 overdrive instead rather than the 0.64 for the SPF coupe. The gear ratio spread is pretty good and drives like a progressive 5 speed unlike the 0.64 OD which has a large spread between 4th and 5th and drives like a 4 speed with an OD. Your top end is limited to 180/190 mph with the 0.8 gear depending on your red-line. Use the 0.64 overdrive if you want faster top end or are looking for economy on long drives. The TKO is stronger than the T56 and is a little shorter as well as a little lighter, quieter and shifts smoother. I took Dennis' advice and installed the TKO 600 with the 0.8 overdrive and it works just terrific. You should let SPF know if you are using the TKO 600 so they will prepare your car for the shorter tranny. My car was in the 3/07 issue of C & D and, even down 80 HP with restrictive velocity stack screens, it still did 0 - 60 in 3.7 secs, 0 - 100 in 8.4 sec and the 1/4 in 11.9. It did the rolling 5 - 60 in 4.2 sec and smoked everyone in the top gear 30 - 50 in 4.7 sec and 50 - 70 in 4.1 sec. I guess you can say the TKO 600 with 0.8 top gear works just fine the the SPF coupe. BTW, the article got it wrong about my top gear. They erroneously reported it as 0.64. They also got other things wrong but that's another story. . .
Oh, re Peter Brock's coupe pulling 1.07 G's in the March '06 R & T, using Peter's old many heat-cycled Kumos on a very dirty track, my coupe, in street set-up with a retail alignment shop alignment, pulled 1.12 G's on the skid pad.