For working angles to be the same this is true from what i've been reading, but that would end up giving me alot of positive pinion angle under load, which is what im most worried about.

Im either going to mount new spring perches to correct it, or just bite the bullet and go 4-link or ladder bar.

 

Well for anyone who'd like to know, i welded new spring perches in today. I used jackstands and an old driveshaft to set up a sort of "jig". Then i set the angles to exactly what i measured on the truck. I then measured the spring perches at -2*. So i rotated the pinion downward and kept measuring until i ended up with -6* of pinion angle. If your doing this remember that the driveshaft angle is also going to change when you rotate the pinion, so keep measuring both, not just the pinion. Once i got it where i wanted it i wrote down the measurements and cut off the old spring perches. Then with the pinion pointing at the angle i wrote down i positioned the spring perches at -2* and welded them on. Then i just put it all back together.

Now for the results. The vibration i used to have is gone from what i can tell so far, and traction has definetly improved. Traction improved to the point that i get wheel hop now, which i never had before with spring clamps, once they started spinning before they would just keep going. So 2 steps forward and 1 step back i guess, but its getting there.

 

On leaf springs we usually try to run -4 degrees and -6 on high hp apps. Thats with the tranny output shaft at 0 though.

 

Im running it kinda high based on the recommendation of my local speed shop. The combination of fairly high hp, leaf springs, and a manual tranny makes for alot of shock to the drivetrain. Plus if i ever get it to hook i'll be running a healthy dose of nitrous on it as well.

 

Sounds like you're getting there. Keep at it!