'98 Z28 LS1

[Rev]

BennyBoy, the Jeep and all late model cars have over drive and so can use a 3.73 or a 4.10 with no problem. They cruise at 70 mph at 2500 or so. With the C-4, we don't have that advantage (over drive) so we can't use those as well and still cruise at a decent rpm.

Gross hp as was used before 1970 is about 25% higher than net that we use now. Or to say it another way, net is about 80% of gross. Standard shift drivetrains have an effiency of about 83% according to Ford. Automatic drivetrains are usually considered about 78-80% efficient for newer ones and possibly as bad as 75% for our old C-4's. That means we only put 75-78% probably of our net hp to the rear wheels.

Hope this helps a little.

Rev