rear axle angle

[mtnman15849]

i'm building a 79 GMC K10 short bed Stepside,,8 inch lift, got a cucv 14ff for the rear so i need to move the spring perches from 40 1/2 to 42 1/2 i think,,i got a set of perches from blue torch fab,, I'm thinking about using a 4" shackle flip from ORD,, HOW DO I FIGURE THE PROPER ANGLE?? can this be done without a trial fit?

P.S. i have an extra brand new cucv dana 60 king pin front axle complete except hubs for sale

[BravadaMan]

Well, the BEST way would be to trial fit it. Not that hard to do. It also depends on what type of driveshaft you're going to run as well. If you are going to run a CV driveshaft, you have a bit more leeway that with a "standard" 2-ujoint driveshaft. The standard 2 ujoint driveshaft, the pinion has to be parallel with the tcase output. In a CV driveshaft, you would usually point the pinion right at the tcase output. Also, if it's gonna be pure offroad and you don't mind a bit of vibration, angles aren't that big of a deal (within limits of course.) Just my $.02

[83GMCK2500]

This article should answer most of your questions. It is really detailed and covers all of the important parts.