The Sandersons are tubular steel and fit fine. The Chevy ram horn manifolds are old, cast iron, and look funny, but flow as good as headers and cost a lot less. The only clearance issues with the '88 cars is the narrow cradle. It all fits, though.
I had to use tall covers to clear my aluminum rockers. I was going to use a solid lifter cam, but switched to hydraulic. Look at the pics HERE and you will see why. I used the bottom holes on the front mount and made solid tranny mounts from 1-1/2" square tubing. There is no way I'm getting those covers off without swinging the cradle. Low profile covers and use of the lower holes will make cover removal possible.