I apologize ahead of time for bringing this up again but the confusion continues. I'm getting a vibration I think is coming through the driveline, at least I would like to make the necessary adjustments to eliminate as a possible cause. I've read all the info (on this site and other sources) associated with this subject, which is extensive, until I'm brain dead & I'm not sure I completely understand it. I used a digital angle gauge & the Spicer Driveline Angle Calculator to come up with the specs. According to the specs there is a difference between of 2.5* between the two operating angles which violates the recommended limits (1*). I have a live axel in the car with the FFR 4 link fixed length upper & lower control arms so the angle of the pinion is not adjustable. The flange of the pinion points down (slopes) towards the ground around 2.5* (the Spicer Calculator considers this as "up slope" though when inputting the data). The angle of the eng/trans also slopes in the same direction as the pinion ("up" in Spicer terminology) about .5*. The driveshaft slopes in the opposite direction ("down" in Spicer terminology). If I understand the theory of needing to put the two operating angles in parallel planes within acceptable tolerances (1*) I would need to shim the rear of the transmission up slightly? I guess I could also drop the engine mounts down some too if possible? According to the Spicer Calculator I would have to set the eng/trans at around 1.5*-2* "up" to obtain the proper alignment.

Does it sound like I'm headed in the right direction with this thinking?

Is there any issue running the eng/trans at this direction of slope?

I would appreciate any input you guys might have.

Thanks,

Glenn