I would replace the originals, they should still be available, and the bolts also, I know that a similar locking tab like that is used on exhaust bolts on the chevy 454s, I dont know if they are the same size as that one.
also I am not fimialar with the stuff you took that off of, so no help there. you might be able to find some at one of the chevy or gm dealership that would work, just take that one for a size comparison, good luck Mike B
