Hey everyone, is it possible to set the pinion angle in the rear end without having a transmission or drive shaft yet? I am trying to install a triangulated 4 link set up on my 49 Chevy Styleline Deluxe and the pinion angle is confusing me. Any help is appreciated. Thanks!
Of course you can at least you can get it close enough for govt work. The car is going to settle a little bit with the transmission installed but not much depending on what you use for a transmission. The pinion should be parallel to the crank or the transmission tail shaft which will be parallel to the crank.
Your links should come with at least one end threaded. Get the fab close with setup, fine tune when all the parts are installed. You could possibly set the frame level, use a dummy / junk engine and trans (even just the crank flange) set at the final angle, then adjust the diff accordingly. Or just tack the 4-link brackets on and re-position later.
Are your four link bars threaded ends? If so, you can adjust the pinion angle. The 3 degrees up is a good starting point, your trans output is likely to be a few degrees down.
Pinion angle is nearly the same angle as the intake manifold carb flange. If you are using OEM style intake it is about 3deg so the engine angles downward by 3deg to get the carb sitting level. Convention says pinion would go up at same angle. If you have aftermarket intake that is flat the engine would sit level so I'd tip the pinion down by a degree and let it go. If it is down when under power it'll come back level to match the engine.