1965 BB Bell Housing

[Joel T.]

Can anyone confirm that the correct bell housing for a 1965 BB car is part number 3858403? The Judging Guide says it is but as I crawl around under the car what's in there now looks nothing like any 403 I've ever seen...

Thanks, Joel

[John S.]

Re: 1965 BB Bell Housing

Joel,

403 is the correct bell housing for the 65 BB. There have been some discussions that a 383 was also used.

[Joel T.]

Re: 1965 BB Bell Housing

John,

Ah... maybe that's what is in there now, Thanks! J

[Mike M.]

Re: 1965 BB Bell Housing

403 works for me. doubt 383 ever used in any 65 396 vettes--that's the one for the later big blocks with larger flywheels. mike

[Wayne M.]

Re: 1965 BB Bell Housing

Mike -- you're probably thinking of the "621" with the 427's.

But I wonder about the categoric statement in the '65 TM&JG that ONLY 403 manifolds were used for 1965 MY. There are too many instances of "383"s sporadically popping up on late '64s, early '65s, IMHO.

[Joe L.]

Re: 1965 BB Bell Housing

Wayne, et al------

The GM casting #3840383 and GM casting #3858403 bellhousings are near-identical bellhousings and, as far as Corvettes are concerned, are 100% interchangeable.

The GM casting #3840383 which was actually of GM PART #3840381 was supposed to be the bellhousing used for 1964 Corvettes with manual transmission. Apparently, though, the 3858403 was used for many or most 1964 Corvettes.

The GM PART #3840381 bellhosuing was discontinued in January, 1965. It was replaced at that time by the GM PART #3858401 which, I believe, carried casting #3858403. In June 1966, the GM PART #3858401 was discontinued and replaced by GM PART #3858403.

So, what are the differences between these bellhosuings? Well, they are identical except for these features:

1) Generally, the GM CASTING #3840383 has no bosses on either upper side of the bellhousing. However, I have seen a few 3840383 that did have a boss on the upper left side of the bellhousing which was drilled and tapped for 1/2-13 thread;

2) The 3858403 has bosses on either just the left side or BOTH the left and right side. The left side boss is always tapped for 1/2-13; the right side boss is usually not drilled and tapped.

The bosses described above were used for clutch cross shaft mounting for certain Chevrolet models (Chevy II was the primary, if not the only, model for which this was used). So, the bosses were completely unused for the Corvette application making either the '383' or the '403' equally functional for Corvette applications.

So, why the right side boss on some '403' bellhousings? I wondered about that for years. John Hinckley answered that question some time ago. It seems that some Chevy IIs were built with right hand drive for export. So, they required the right hand boss for the clutch cross shaft.

[Philip C.]

Mikie Your 0 for 2 on bellhousing LOL Phil *NM*