C2 Bellhousing Part Number Help

[Alan Drake]

OK, just read the JG and the list of possible bellhousing numbers due not match what I have. I have 3872444 and 3840383 do not know where the extra bellhousing came from except most extra parts came from a 63 250HP car. Have documented car back to spring of 1966 and bellhousing was not changed.

Any ideas Thanks for Help

[William C.]

Re: C2 Bellhousing Part Number Help

What year and engine are we looking at? Neither is correct for the '63, but both were used in various applications in later years, so the year and engine combination you are working with would be very helpful.

[Joe L.]

Re: C2 Bellhousing Part Number Help

Alan-----

Neither bellhosuing is correct for a 1963 Corvette. 1963 with manual trans used a one-year-only bellhousing of GM casting #3788421. This bellhousing has a smaller transmission bearing retainer hole than later (or, earlier) Corvette bellhosuings. It was used for all 1963 Corvette whether 3 speed or 4 speed manual transmission. This bellhousing is designed for use with a 12-3/4", 153 tooth flywheel which all 1963 Corvettes used.

Your GM #3872444 was first used for the 1966 model year for L-72 and L-36 applications. It's designed for a 14", 168 tooth flywheel. I can guarantee you that no 1963 Corvette ever originally used this bellhousing; it hadn't been "invented" yet.

The GM #3840383 was used for some 1964 Corvettes and may have been used for some 1965, too. It has the "standard" transmission bearing retainer hole as used for all 64+ Corvettes. It's designed for use with a 12-3/4" flywheel. It's completely interchangeable with the GM #3858403 bellhousing which was used on the majority of 64-67 small blocks (and L-78 and L-88 big blocks, too).

[Alan Drake]

Joe's got the answer, but . . .

Sorry for not giving the needed info. It's for a Mar64 FI, 4sp.
Know where the 3872444 came from - a 66 427 we used to race.

So my 3840383 that's been used since spring 66 is corrrect, however its not listed in the JG so points lost.

Joe, is there any documentation I can obtain to show the judges at a show that the bellhousing is a good number?

Thanks

[Joe L.]

Re: Joe's got the answer, but . . .

Alan-----

I feel very sure that some 1964 models were produced with the 3840383 bellhousing. In fact, I think that MOST 1964 models had this bellhousing. I don't think that the 3856403 even existed as of the start of the model year. There was no reason for it to exist, either. The only difference between the 3840383 bellhousing and the 3858403 was a boss on the upper left side (and, for some, both upper left and right sides). However, I don't think that there was any 1964 application which would have required the boss. Corvette applications NEVER required the boss.

Also, the October 1, 1963 edition of the P&A Catalog (first edition for the 1964 model year) and the October 1, 1964 edition of the P&A Catalog both show bellhousing GM #3840381 (the PART number for the bellhousing cast 3840383) as the bellhousing applicable to 1964 Corvettes. In fact, the October 1, 1964 catalog shows that the 3858403 as being applicable to 1965 models ONLY. Later, the 3858403 became SERVICE for 1964 Corvettes.

The survey for the 1964 model year shown in Noland Adams' book indicates 5 cars surveyed as all having the 3858403 bellhousing. Quite frankly, I question whether some or all of these have their original bellhousing. They may have been "made original" with '403' bellhousings to conform to the JG. The '403' bellhousing is very easy to find, inexpensive, and a lot less rare than the '383'. Plus, they have no meaningful (i.e. with YEAR) date code on them, so there's no way to know when they were made.

[William C.]

Re: Joe's got the answer, but . . .

From a judging standpoint, the part number in the JG is primarily for information rather than for use in judging. Many of us (most?) can't get that far under the car.

[Alan Drake]

Re: Thanks to Joe

Thanks for your info, I will use a copy of Adam's book which shows a 0383 bellhousing and try to get a copy of the Oct 1, 64 P&A Catalog for Group 0.683 showing the 0383.
Sometimes the part number v casting number can add more confusion to all this stuff (at least to a non expert).
Thanks again
Alan

[Michael H.]

Re: Joe's got the answer, but . . .

I agree. I believe the 3840383 housing should be added to the 63-64 JG as having been used for at least part of the 64 model year.