i got a heidts 4 link for my 56 and need help with it ,,, motor is 3degrees down
internet says my rear end should be 4-4.5 up
is this correct before i start welding...... what are you guys setting it at for best results

 

Pinion angle and crank angle need to match (be parallel), with the vehicle and suspension at ride height. Suspension type makes no difference. This is about u-joint operation and drive line vibration. If the engine is pointing 3 degrees down, you want your pinion 3 degrees up. 4.5 is too far out, imo.

 

The beauty of a 4-link is that the pinion angle is fully adjustable after installation by lengthening/shortening the bars. While it is true that the ujoint bearing need at least 1 degree variance the properly lube themselves, I don't think it possible to set up a driveshaft at zero degrees... 1 degree ain't much.

 

I followed this logic when I installed my no limit 4 link a few years ago. Can confirm it works great with no premature joint wear or weird vibrations. Great summary!