Re: Motor mount bolts
Now I think I know what "threw me off" on this one. 1964 to 1973 Corvettes did use the GM #3748038 bolt assembly as has been discussed and described above. However, 1974-82 Corvettes used a different bolt. This bolt was GM #331246. It was a bolt which did not have a captured lockwasher and, instead, was used with separate lockwasher GM #103321. It was gray phosphate-finished, 3/8-16 thread size, and GM-300M material grade (SAE grade 8). The NOS examples I have are trimmed (i.e. "non-indented") head but I don't know that all examples of this bolt ever made are trimmed. Note also that this is a special bolt. It is 7/8" in overall length and has a short unthreaded shank under the head which is uncommon for a bolt of this length.
DSCN2687.jpgDSCN2689.jpg
Now I think I know what "threw me off" on this one. 1964 to 1973 Corvettes did use the GM #3748038 bolt assembly as has been discussed and described above. However, 1974-82 Corvettes used a different bolt. This bolt was GM #331246. It was a bolt which did not have a captured lockwasher and, instead, was used with separate lockwasher GM #103321. It was gray phosphate-finished, 3/8-16 thread size, and GM-300M material grade (SAE grade 8). The NOS examples I have are trimmed (i.e. "non-indented") head but I don't know that all examples of this bolt ever made are trimmed. Note also that this is a special bolt. It is 7/8" in overall length and has a short unthreaded shank under the head which is uncommon for a bolt of this length.
DSCN2687.jpgDSCN2689.jpg
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