This 1988 c4 engine blew in 2020 so I rebuilt and went with a naturally aspirated 383 stroker kit. It has a 700r4 automatic transmission. I have replaced all calipers, master cylinder, and bled everything twice (no, not exaggerating). The problem i am facing is that the rear driver side wheel locks up so it won’t move. To test what was happening , I put it up on jacks so all wheels can turn freely. Once up on jacks, I discovered that the wheel will only turn when the lug nuts are slightly loose. So i took the wheel & caliper off and made sure the piston was fully depressed. when assembled again i found it was still too tight to let the caliper spin even a little bit. So I ended up taking out the pad that sits against the piston and re-installing to see if the rotor would turn without the pad in there (curious if the caliper body was hitting the rotor). It did turn fine so I assumed it could only be the pad was too thick (keep in mind all the other wheels spin fine with the same set of pads). having no other option, I ground down the back of the pad .1 of an inch to see if that would give me the clearance I needed. Put everything back together and tested by putting some lugs on the rotor just to simulate a tight rotor and the rotor was indeed able to spin without any problems. I then put the tire back on. Once the lugs were tight, it refused to move again. The car has never been in an accident and it wasn’t doing this before I rebuilt it, so something must different with the new calipers… but am I missing something?

 

Welcome to the forums. Yes that is strange. What's the condition of the wheel bearing? If the bearing has too much run out (play) it can put too much pressure on the caliper from the rotor,If that's the case the wheel would turn freely when jacked up. If that's not the case it could be the caliper wasn't machined right where it's mounted to the wheel assembly, if that's the case you can replace the caliper or shim the caliper where it mount's to the wheel (shimming the caliper inward),(rotor binding) to check that theory, mount the wheel (while in the air) Loosen the caliper mounting bolts a few turns and see if that makes a difference. If that's better try shimming, That is what I would check first.

 

Ok got it. Thanks for the expertise! I honestly had no idea what to even try next