Help with part number please(C-2)

[Randy Adams]

What does a bell housing with GM 3840383 fit. It is not mentioned in the judging manual. Thanks for your time.

[Mike Cobine]

Re: Help with part number please(C-2)

ID # 3840383 is p/n 3858403. It fits
'65-'67 Chevelle 283 exc HD clutch;
'67-69 302 all;
'70-73 307 all;
'64-69 pass 327, '65-68 Chevelle 327, 67-68 Camaro 327, '69 Chevy, Chevelle, Camaro w/reg fuel 327;
'69 pass 350 exc taxi, HD clutch; '69 Chevy, Chevelle, Camaro w/reg fuel.

It also lived on various 6 cyl from 1964 to 1975, the 262, and so on.

[Mike Cobine]

Now the Corvette applications

1964-1968 327, 396
1966 427 w/SP, H/PER
67-69 427 HD, AL CYL and CASE

[Mike Cobine]

Disclaimer

These numbers are in the Chevrolet parts book and are the service parts available over the counter. They may not necessarily match the original production numbers.

[Randy Adams]

Re: Disclaimer

Thanks Mike that was a lot of work. I appreciate it.

[Joe L.]

Re: Help with part number please(C-2)

Randy-----

The applications for the GM #3840383 bellhousing are pretty much as Mike described. However, this is sort of a "complicated" situation as far as it all goes.

GM #3840383 was the CASTING number for the GM PART #3840381 bellhousing. This bellhousing may have been used exclusively or in combination with GM CASTING #3858403, on 1964 and earlier 1965 Corvettes. I doubt that the GM #3840383 casting was used in PRODUCTION after 1965. It's possible, but I doubt it.

The GM PART #3840381 bellhousing was discontinued from SERVICE and replaced by the GM #3858401 in January, 1965. GM PART #3858401 carried CASTING number GM #3858403. It was an identical bellhousing to the 3840383 EXCEPT that it had a boss on the left side of the upper portion of the bellhousing for the purpose of clutch cross shaft attachment for Chevy II models, which also used this bellhousing.

GM #3858401 was discontinued in June, 1966 and replaced by GM PART #3858403. This bellhousing PART number had bosses on BOTH upper sides. Although the casting number remained the same as earlier used for the GM PART #3858401 bellhousing, the drawing for the part was, apparently, revised to include the right side boss. I always wondered what this right side boss was for; the only thing that I could imagine was right hand drive and I didn't think that any Chevy IIs ever were built with right hand drive. Sometime ago John Hinckley solved the mystery when he reported that some Chevy IIs WERE built with right hand drive for export. So, this has to be why the right side boss was added to the bellhousing.

In any event, the GM CASTING #3858403 bellhousing was used for most L1965-68 Corvettes with small blocks and also 1965 L-78 and 1968-72 Corvettes with L-88, ZL-1, and ZR-1. It's also possible that the 3858403 bellhousing was used for some 1964 Corvettes, while others received the GM #3840383. My strong suspicion is that IF any 1964-E65 Corvettes were originally built with the '403' bellhousing, then they were built with examples WITHOUT the right side boss. After 1965, I expect that they may have had either the left side boss only or bosses on both sides. Also, I think that by the time that the L-78 option appeared for 1965, the GM PART #3858401 (CASTING #3858403) was probably in use, so I would expect most 1965 L-78s to have the '403' bellhousing (with left side upper boss only). It's possible that some real early ones had the '383', though.

Although GM parts information does indicate that the GM PART #3858403 bellhousing carried CASTING (or, ID number) "3840383", I really don't think that any GM PART #3858403 bellhousings carried this number. I think that this reference is incorrect and, likely, an "anachronism" that "crept into" parts information.

While the GM CASTING #3840383 was likely only used in PRODUCTION for some/all 1964-E65 Corvettes with small blocks, it is 100% functional for ALL 1964-68 Corvettes with small block + all L-78, L-88, ZL-1, and 70-72 ZR-1. As I mentioned, the only difference between the '383' and '403' castings involves the upper boss(es) and these are unused for ALL Corvette applications. So, while many Corvettes were originally built with bellhousings with the bosses, and, consequently, need said bosses to be "correct" today, the bosses were totally superfluous for Corvette applications. In that sense, the '383' bellhousing makes for a "cleaner", if incorrect, installation for most 65-68 Corvettes with small blocks + L-78, L-88, ZL-1 and 70-72 ZR-1.

[Randy Adams]

Re: Help with part number please(C-2)

Thanks Joe, you are a wealth of information to all. Just for your info. the "383" bellhousing is on a very early '64 w/327/300 hp. Thanks again.

[Joe L.]

Re: Help with part number please(C-2)

Randy-----

VERY, very likely the originally installed bellhousing.

[Jim S.]

Re: Help with part number please(C-2)

Joe,
Two more questions in re 403 bellhousings...what does the single number above the 3858403 mean and.... when did they turn the ....403 upside down, if you know what I mean ?

Jim

[Joe L.]

Re: Help with part number please(C-2)

Jim------

I'm afraid that I don't know the answer to either question.