by akaFrankCastle » Sun Nov 14, 2010 3:24 pm
Are you running a 3spd or C4?
In either case, you'll be look at around 2300 RPM at 65 MPH, 2500 @ 70.
If fuel economy is going to be a big concern or you are planning lots of highway driving, you might consider swapping over to a ZF 5 speed. The ZF will get you 1900 RPM at 70MPH with the 3.50s and 2200 RPM at 70 MPH with 4.11s.
All of these numbers are based on your 33's. Going up in tire size will lower your RPMs, but now you need more juice to push that rubber, plus suspension mods to clear everything.
Kind of a dual edged sword all the way around.
Stroppe'd
1972 Sport, 302, 3 speed with old school Duff floor shifter, T shift Dana 20 with JB Fab twin stick, 4.11 gears with Trac-loc, Lincoln hydroboost, Chevy disc conversion, WH gas lift gate shock kit, 33" Duratrac tires on slots and about 2.5" of lift, Stroppe installed: bumper braces, dual shocks on all four corners, GM power steering, trans cooler mount, auto shift column, rollbar.
The Terrible One
1972 Sport uncut, 302, C4 with 1974 column , T shift Dana 20, 3.50 gears w/ limited slip, 1966 U13 Roadster kick panel, and factory power steering.
1973 Stroppe Baja project