Hello,

I have installed C4 transmission and 9” rear. The driveshaft U-joint angles are high, if I understand the concept correctly.

Specs:
Crankshaft/output shaft:         .5 degrees down  =     9 degree operating angle
driveshaft:                             9.5 down
pinion:                                   1.5 down                =     8 angle

I have gathered that less than 3 degrees u-joint operating angle is desirable. At 9 degrees Spicer lists safe operating rpm to be 2000, the engine is built for 6000.

The driveshaft is 31.5” long, using a right angle calculator, the rise is around 5”, to get to 3 degrees the rise must be around 1.5”, The T-bird x-member frame and distance to the pinion make this seem impossible to me. I could raise the pinion .5” more, but that does little to the operating angle. I believe the T-birds have a steep driveshaft angle from the factory; I did not measure the specs before I took it all apart, never considered driveline angles at that point. I never had a problem revving it up back when I drove it 35 years ago.



.150 Stroked Y-Block:327.25 ci @ >1hp per ci