[del4fun]

Originally Posted by RustyBucket

Goodrich says my 275/60/15 T/A Radial is 28" tall. My '71 GMC step-side has a 3.08 rear, 700r4, and a mild 350 engine. First gear in the 700r4 is a low 3.06 ratio, so the truck jumps off from a stop good. Under light throttle it shifts, 17-20mph. Pretty big gap in ratio first to second gear(1.63) but it pulls it ok and keeps up with traffic good. Shifts itself under light throttle again around 30mph. and in 3rd gear ratio is 1.1, just like top gear in a Turbo 350. A lot of the time driving around town I bump the shift lever up 1 notch so it doesn't go into overdrive. If I don't do that it will shift itself under light throttle into O.D. around 50mph. I don't have a tach. in the truck but engine just feels "happier" turning a few more R.P.M.s. Mileage isn't great. I do baby the transmission a little 'cause I don't think it will stand much abuse..... I run the pee out of my Blazer anytime nobody's lookin'.
Looks like with 3.73's that low first gear would be mighty short.

4.10 it is , thanks