3899621 Bellhousing

[Tom W.]

Discovered my 71 M20 bellhousing has a large crack along the inside (from center to about 2 o'clock position).
The crack feels jagged along the inside but not visible from the outside. Looks like it's been there for a while.
I assume I need to replace the housing, but thought it wouldn't hurt to get some experienced opinions from the forum.
Also want to double check that NRS does not verify any of the numbers on the bellhousing.
Any suggested source for a nice replacement?
Thanks

[Joe L.]

Re: 3899621 Bellhousing

Discovered my 71 M20 bellhousing has a large crack along the inside (from center to about 2 o'clock position).
The crack feels jagged along the inside but not visible from the outside. Looks like it's been there for a while.
I assume I need to replace the housing, but thought it wouldn't hurt to get some experienced opinions from the forum.
Also want to double check that NRS does not verify any of the numbers on the bellhousing.
Any suggested source for a nice replacement?
Thanks

Tom------


It could be welded by an experienced aluminum welder. I don't think I'd do it, though. I think it would be best to find another un-cracked bellhousing. I think you'll find plenty of these for sale on eBay. This is not a rare piece, at all, and was used on all Chevrolet models from 1967+. There's even a very good reproduction on the market now.

There are no meaningful dates on these bellhousings. However, if you decide to go the replacement route, I would look for one that has the "GM" logo and part number in the same location and script as your original. Examples like this are not rare, either.