67 big block bellhousing casting #

[Rob A.]

I removed a #444 bellhousing from my 67 400hp, with M21. Is this considered to be a correct, original piece based on the #.

[Joe L.]

Re: 67 big block bellhousing casting #

Rob-----

It may very well be original and correct if your car is an early-build 1967. Most 1967 Corvettes with 427 used the GM #3899621 bellhousing. However, some early cars may have been fitted with the '444' bellhousing, which is, primarily, a 1966 big block bellhousing. Except for the casting number and the configuration of one of the reinforcing ribs (the one at about the 10 o'clock position as viewed from the rear of the bellhousing), the 2 bellhousings are identical. The reinforcing rib in question of the '444' bellhousing is narrow and "high" like the rest of the ribs. The corollary rib on the '621' is wide and flat. I'm sure that this change was made to accomodate some other 1967 chassis configuration as the '621' bellhousing was widely used across most Chevrolet car models with 14" flywheels and 11" clutches from 1967+.

I believe that the 1967 NCRS Judging Standards allow for the '444' bellhousing on early-build 1967 Corvettes. In any event, the '444' is a lot rarer than the '621', so if you want to sell it and purchase a '621', you'll come out to the better.

[John M.]

Re: 67 big block bellhousing casting #

Is it true that some of these bellhousings are used for both small and big blocks? I think the Noland Adams survey shows the same numbers with the different engines available that year.

[Joe L.]

Re: 67 big block bellhousing casting #

John-----

As far as I know, the '444' bellhousing was never originally used for any small block application. Certainly, it was never used for any Corvette small block application. The '444' was, primarily, a bellhousing used for 1966 and early 1967 big block applications in Corvettes and other Chevrolet car models, particularly Chevelles (which is the major "donor" source for this part number).

The GM #3899621 bellhousing which succeeded the '444' in early 1967 was primarily, if not exclusively, used for big block applications during the 67-68 period. However, beginning in 1969 when the 14" flywheel/11" clutch became widely used on BOTH small blocks and big blocks, the 3899621 became widely used on both type engines. For the 69-81 period on Corvettes, the 3899621 is, far-and-away, the most common bellhousing.