[Anthony]

Ant, to me, the gold standards of close ratio mass produced trannys are the muncie M21/22 and the close ratio toploader, of which the muncie has closer spaced gears, I think 2.20/1.64/1.27/1.0 compared to the toploaders 2.32/1.69/1.29/1.0 . I did a search on the LeMans racing vipers/vettes, and couldn't find any specs on the tranny gears, but I did find that GM offers a road race T56 for the vette, only an over the counter $8000 option, for scca racing. The gear spread was 2.29/1.61/1.22/1.0/0.85/0.75 , which is a lot closer than what the T56 is offered in the street camaro's, vipers, vettes. To me, this is a true close ratio 6 speed, and is probably close to optimal gear spacing for a V8 powered mid sized race car.

If you got a custom 5 speed tranny, with the first 5 gears similar to this, basically a muncie/toploader with a 15% - 17% overdrive, I think this would be the best overall gear spacing.

As the jerico and G-force trannys have 5th gear as 1:1, you would have to adjust the muncie gear ratio's, dividing each number by 0.85, to come up with a 5 speed as can be offered/designed. So, 1st would be 2.59, second 1.93, third 1.49, fourth 1.18, and fifth 1.0 , and this should be fine with a 3.07 rear. If you want a 17% overdrive, then divide each gear by 0.83, so the rato's would be 2.65/1.98/1.53/1.20/1 , etc.