Roger, I don't know if this is still something you're searching for, but I just spoke to Chris at
Turbo Kraft in AZ about this very same problem. He can make a custom set of insulator blocks that taper
from and
to whatever size you need. He quoted me $120 for the blocks themselves (no studs/bolts).
-Sounds like you already have a set of blocks, so you possibly won't need new studs/bolts. I think insulator blocks come in varying heights, so you might want to pull one off your car and measure it so they can match that height on your new set.