Pinion angle at transmission mount
My 72' El Camino had worn air shocks so I replaced them with conventional shocks, I also installed
HD rear coil springs so it would have a slight forward rake. This isn't a Drag car or daily driver, just something for weekend use (Plus the Hot-Rod Power tour). Anyway, after I finished I took it out for a ride and there was a vibration coming from the driveshaft/Rear-End (Pinion angle). I had the same vibration with my 39'Ford Coupe when I built it, years ago. That was and easy fix because all I had to do was find the right angle and use (3 degree) wedges over the leaf springs, but coil spring suspension is a bit more complex. I hate to spend the money on rear adjustable control arms so instead I took a ride to the local parts store to see if I could find a shorter height transmission mount to lesson the angle, but no luck & I don't know of anyone who makes them either. Before going for the adjustable control arms I was thinking of raising the motor mounts with a plate or washers which is another cheap fix...
Anyone run into this problem with a coil spring rear suspension?
PS: This is a completely stock 1972 El Camino with a 350, a/t & 12 bolt rear-end. It has all the smog stuff still on the car including the air cleaner.
It sat in a garage on jack-stands for 25 years and is in great condition.