Not much has been posted on the difference in pinion angle between the straight shackle and the double shackle. Due to uncapable welders i do not want to reweld the spring perches at this time so which is better on pinion angle? or have many of you even cared and just run it as it is?

I'm curious to know if i need to factor spring perches into my downtime

Thanks
Kevin

I used 6 degree wedges, pinion is almost exactly in line with driveshaft.

Using a double shackle with a 6" shackle laying on the frame and a stock chevy shackle going to the spring, I was .5 degree down on the diff, with 1 degree down being optimal. Close enough for me.

Monte

No matter what shackle setup you have you need to measure the resulting pinion angle and correct it if needed. What correction is needed depends on what sort of driveshaft you are running. If a u-joint shaft, you want the pinion angle 1-2 degrees below the angle of the transfer case flange. If running a CV shaft, you want 1-2 degrees below the angle of the shaft itself:

http://4crawler.cruiserpages.com/4x4/CheapTricks/Driveline-101.shtml#Measurements

when i did mine, i used jeep hangers up front, i built the rear mounts 2x3 box standing tall, w/ a notch to fit the tube which holds the bushings, all in all the frame side shackle bolt centerline is 3" from the bottom of the frame, i used a 5.5" center 2 center shackle. the pinion angle is .5 deg. below the t case flange. i have the 3 leaf chev's with the bottom leaf from the stock rear pack added. no blocks, it sits level with the 4 inch allpro's