I recently had the coils replaced and that helped but I still have about a 1/2" sag in the back. Has anyone tried blocking or shimming the leaf spring to fix the problem? Is that a good way to go and would it affect drive-ability in any way?
1/2”?
That ain’t much. Bet you measure 9 of 10 trucks and they’re off by that much or more.
Heck I was just looking at our “new” truck and it looked a bit off. It’s 1/2 to 3/4” different side to side. Old truck was too, since new. The ‘86 is slightly different.
I wouldn’t sweat it as long as it’s only that much and you make sure no cracked leafs.
You could try a mild re-arch at home if it bugs you. (Stuff like that bugs me too.). Jack up saggy side by the frame, let the springs droop. Fit a jack in between the frame and axle and crank it up. Be careful jack can’t slip out under pressure.
Disclaimer I haven’t tried this for these purposes, but have jacked up a couple trucks stuck good in mud and by the time the wheels popped free, the rear springs had been re-arched.