[robnolimit]

the single shear mounting was done for a couple of reasons. 1. we wanted the bearing centerline to be on the motion line. 2. Ease of installation. It takes about 80,000 lb load to shear a 5/8" grade 8 bolt. With the support sleeve the rate goes up. So, with an average of 750 lbs per side, it would take a 10G hit to hurt the bolt. Honestly, if you somehow create a 10G load impact while driving a C10, you have a LOT bigger problems that any suspension mount.
As to mounting angle, at ride height it is close to 15*. this lessens the spring and shock rate by appx 7%. So, a 250 lb spring becomes 232.5 lb/in. Hmm, x 3 1/2" of static compression = 813 lbs load rate. Compared with 650 lbs of sprung weight per side, x 125% ratio on the trailing arm = 812.5 lbs static load. That's how we do it. Math baby!