Originally Posted by
Padgett
A 2.87 would be close though a 2.73 would be better, without a body mod can only increase the rear tire diameter about an inch.
The problem is that this is not a real 6 speed (5th is 1:1) but a five speed with a granny low. The jump from fist to second is almost 2:1 and while flywheel inertia limits the speed the engine can accellerate, it works against you on a hard 1-2 shift (back in the day we used to lighten flywheels A Lot to compensate).
On the other end, while a 7.6 cDA isn't bad (not great, my Fieros were 6.75) but OK, the 3.2 has plenty of torque for a 1900 rpm/70 mph cruise. Engine would be more efficient there anyway.
Keep in mind that the purpose of an OD is not top end but a relaxed cruise and for our engine geometry (3.3" stroke is near ideal for gasoline) a sub-2000 rpm cruise at 70 mph would work very well.
Math isn't simple, tied up the GMI computers for quite a while in the early '70s calculating ideal engines/trans for different conditions. Since was going to school in Michigan and home was in Florida, many hours at cruise was important to me. Had a 67 Camaro 327 with a late Rochester FI, four speed, & free flowing exhaust that turned in some amazing numbers but had real Sunoco 260 then.
ps I also use OBD-II for RPM and GPS for speed. Is close enough for government work.
sounds ok just let me know if and when you want it ,,,i would then take it to my machine shop, and get it ready for you. jim