the truck has broken 2 nose cones now and I have tried many different shim combinations it sounds best with none but then it eats the starter it is a 77 K10 with I believe a 400 that's what it came with and it is externally balanced incase it matters it has a 4 speed with a 205 transfer case I'm just out of ideas the flywheel looks fine on a tooth by tooth inspection any ideas would be appreciated