Fwiw on the gearing, 90mph/26.5" tire/4.10 gears, no converter slip = 4660rpm.

3.55's put it at just over 4000.

I can't imagine the converter would slip more than about 3-5%.

4.10's isn't a lot of gear when you're running under 100mph in the 1/4.

68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads