I have a 68 with a 454 and Hooker Comp headers. One of the tubes is rubbing the power steering unit and is killing my Jet Hot coating. Is it safe to shim the engine up on the drivers side slightly to give me just a little more clearance there? I'm thinking that a thin plate maybe 1/8"-1/4" would be plenty. I am pretty sure that I have big block mounts already.

Randy, Raising the frame mount would be the best way to achieve the results that you are looking for. However, anything more than an 1/8th of an inch may show the engine shift to the right. YOu might consider shiming both sides. Good Luck.