Not to hijack, but I measured my pinion angle. I found that I am 2 degrees up on the pinion and 2 degrees up on the driveshaft/trans for a total of 4 degrees positive.

The Mopar Performance Chassis book says the pinion angle should be 5 to 7 degrees negative. But that's for a drag-only car I guess.

I've got a street/strip car with Superstock springs. I ordered a pair of 4 degree shims. By my calculations that should get me down to 4 degrees negative (a 2 degree shim would get me to 0, so another 2 degrees would get the pinion down 2 degress plus the driveshaft down 2 degrees for 4 degrees down total). Is that a good compromise for a street/strip car? I've been researching this online and have been coming up with the recommendation of 4 degrees negative a lot. Some will even recommend various amounts of negative pinion angle for various amounts of horsepower. Like 4 degrees down for cars in the 400 HP range and more towards the 7 degrees down end for higher HP like 700 HP and up. Is my math correct? Thanks!