I haven't found a source that defines ALL bolt sizes based on GM part numbers. I have found SOME sites that list SOME bolts, but not all. It takes some detective work and some trial and error.

Unfortunately, the fastener part numbers listed in "Standard Parts" (group 8.899+) in the Master Parts Catalog usually don't match the numbers in the Factory Assembly Manual. Some do / some don't. But it's a good place to start.
> Master Parts Catalog Group 8.899

Here are some sources that I have used ...
> Stovebolt post

I see that the link to GMPartsWiki in the post is broken. Don't know if the site is down temporarily, or if is no longer available.

If you can't determine the correct fastener size, then post a question - go with the answer that you feel is best.

- Lonnie

- Lonnie
My '54 3104
Photos that I have shared on Stovebolt via PhotoBucket are no longer available. Please contact me if you want a photo from an old post.
lonniecook [at] aol [dot] com. I sold my '54 3104 12/12/2017, but I still visit Stovebolt.

OLD STUFF ... houses, furniture, cars, wine ... I love it all