final drive ratio can also bring up some other considerations. Friend of mine with 462" olds in an 87 cutlass with 6 speed manual (5 is .75:1 and 6th is .5:1), 9" ford rear. He autocrosses occasionally, and drives it city/highway/whatever. He's got 4.30s in the back and in 6th its up to 2.15:1! Problem he had to deal with is driveshaft diameter. With that 4.30 gear at 80-85mph, you have some sustained high driveshaft rpm. He had a vibration that stemmed from insufficient driveshaft diameter for the rpm it was running. The engine is just purring along, but that driveshaft is spinning like the knob on the ****house door.
__________________
Clutch Guys Matter
_______________________________________
53 Studebaker, 400P/th400/9"
64 F-85
72 4-4-2 Mondello's VO Twister II
84 Hurst/Olds #2449
87 Cutlass Salon
54 Olds 88 sedan
|