I have the same type of question...
I have a 67 Camaro with an iron headed big block, tire is a 275/60/15 for now, and I have 4.10 gears. From looking at speed calculators, it seems that with the .64 unit, I will be doing 73 MPH @ 2300 RPM. With the .82 unit, I will be doing 57 MPH @ 2300 RPM.
I live in Hawaii, and traffic is sh!t on oahu, plus freeways are not very long. So I'm wondering if I should get the .64 or .82... Jeff at Keisler said I should get the .64, but I'm really wondering if that is the correct choice. My cam in the 468 is pretty big, 290/625 108 solid roller, have a single plain intake, and motor is built to go higher RPM. When I built the motor, we had a 1/4 mile track here, but no more.
if you are buying the overdrive because it has one, make sure you can use it. figure out what your cruising speed will be and then make sure your rpm is high enough for that cam.
__________________
"The WidowMaker"
70 Chevelle Pro Touring - Garage Built, Backyard Painted
Custom 4 Link & Watts, Rushforth Wheels, Ats Spindles, McLeod RXT Twin Clutch, T56 Magnum, C6Z Calipers & Ring Bros Hinges
Special Thanks To: Rushforth Wheels ; Kore3 ; SC&C
Build Thread : https://lateral-g.net/forums/show...ght=widowmaker