396 403 bell housing-any distinguishing features ???

[Anthony L.]

Do the 65 bell housings have distinguishing features? I need to replace one and see 403's with a few variations. Is there a cast date on these things?

[Joe L.]

Re: 396 403 bell housing-any distinguishing features ???

Do the 65 bell housings have distinguishing features? I need to replace one and see 403's with a few variations. Is there a cast date on these things?

Anthony------


These bellhousings were a DIE CASTINGS (unlike the aluminum 1960-62 C1 bellhousings which were sand castings). The "date" is usually seen in a "bisected circle" somewhere on the casting. The upper half of the circle contains a number 1 through 12 indicating the month. The lower half contains dots representing the week of the month. There is no reference to year which makes the date virtually meaningless; half of the bellhousings ever made would be "date correct" for any car. However, I don't think even this is judged.

I have seen a few variations of this bellhousing. Some have a cross shaft boss only on the driver side. Some have a clutch cross shaft boss on BOTH sides (neither boss was ever used for a Corvette application). Some have a drilled and tapped driver side boss, some don't. Those with bosses on both sides usually have the driver side drilled and tapped but the passenger side not drilled and tapped. I've never seen one with bosses on both sides with neither drilled and tapped but they may exist. I've never seen one with a passenger side only boss but they may exist.

In any event, I believe the 1965 L-78 used a 403 with a driver side only boss which was drilled and tapped. However, some may not have had the boss drilled and tapped. I don't know, for sure.

I believe the original bellhousings had the "GM" and the part number in "old style" script. Unfortunately, I can't really explain what I mean and I'm not inspired enough to go out and dig out a bellhousing to picture it. However, once again, there were probably a lot of molds being used at the time and there very well may have been minor variations between them.

Addendum:

The script style and overall configuration I'm talking about can be seen in eBay item #261161750925. Saves me from having to get one out. Also, it's possible that some 1965 '403's' had an untapped boss on the passenger side. I believe the right side boss was added for right hand drive 1966 Chevy II's but I suppose it's possible the '403' with the right side boss was in production prior to the 1966 model year.

[Cecil L.]

Re: 396 403 bell housing-any distinguishing features ???

The Chevy II used a different bellhousing due to the clutch arm being at 7 o'clock.

[Wayne M.]

Re: 396 403 bell housing-any distinguishing features ???

Do the 65 bell housings have distinguishing features? I need to replace one and see 403's with a few variations. Is there a cast date on these things?

For the '65 L78, Tonawanda was generous with the orange paint and covered the entire B-H. Here's what I believe is the original on my late July/early August car. Obviously hasn't been repainted .

[Bill W.]

Re: 396 403 bell housing-any distinguishing features ???

DSC_1404.jpgDSC_1405.jpgWayne I have 2 403s one I think is the original to my car (17346) It had almost no orange including the clutch fork and boot . and the 2nd was a swap meet buy . The original and the swap meet part have the casting reversed from each other , also the swap meet part is drilled on the rt side and has a sleeve or collar in the hole . The stamping boss on the swap meet part is about 1/8 to 1/4 wider than the original .

[Anthony L.]

Re: 396 403 bell housing-any distinguishing features ???

Well, I don't feel so bad now. I thought there might be some continuity of the parts used on the 65 l78. Interesting replies.

[Joe L.]

Re: 396 403 bell housing-any distinguishing features ???

The Chevy II used a different bellhousing due to the clutch arm being at 7 o'clock.

Cecil------


Yes, you're right. It must have been some other right hand drive chassis application that used the passenger side boss for clutch fork ball stud. The thing is I can't recall any other application besides Chevy II that used a bellhousing-mounted clutch fork ball stud, either conventional left hand drive or right hand drive. There must have been some, though.

[Joe L.]

Re: 396 403 bell housing-any distinguishing features ???

Well, I don't feel so bad now. I thought there might be some continuity of the parts used on the 65 l78. Interesting replies.

Anthony-----


There was actually another bellhousing that could also have been used. This was the GM #3840383. This bellhousing is virtually identical to the 3858403. I believe the 3840383 was used on many 1964 Corvettes, especially early examples, because I don't see how the 3858403 could have been released in time for 1964 PRODUCTION, especially early 1964.

Some examples of the 3840383 have no clutch cross shaft boss on either side. Some have just the left side boss and some have bosses on both sides. Of course, no Corvette ever required these bosses so even the "no boss" style of the 3840383 could have been used on any 1964-68 Corvette with 12-3/4" flywheel.

[Wayne M.]

Re: 396 403 bell housing-any distinguishing features ???

[ATTACH=CONFIG]52164[/ATTACH][ATTACH=CONFIG]52165[/ATTACH]Wayne I have 2 403s one I think is the original to my car (17346) It had almost no orange including the clutch fork and boot . and the 2nd was a swap meet buy . The original and the swap meet part have the casting reversed from each other , also the swap meet part is drilled on the rt side and has a sleeve or collar in the hole . The stamping boss on the swap meet part is about 1/8 to 1/4 wider than the original .

Here's a shot of the clutch fork dust boot that was on my 403 bellhousing. I saw it was cracked about 1993, so I ordered another (tags in background) and the (original ?) crumbled when removed. You can see the orange overspray.

A while ago, someone (John Hinckley or Michael Hansen ?) posted a B & W photo of big block engines on the rack at either Tonawanda or (delivered) in St. Louis. You could clearly see the orange (or at least non-silver) finish on the entire bellhousings.

[Joe R.]

Re: 396 403 bell housing-any distinguishing features ???

Here's a shot of the clutch fork dust boot that was on my 403 bellhousing. I saw it was cracked about 1993, so I ordered another (tags in background) and the (original ?) crumbled when removed. You can see the orange overspray.

A while ago, someone (John Hinckley or Michael Hansen ?) posted a B & W photo of big block engines on the rack at either Tonawanda or (delivered) in St. Louis. You could clearly see the orange (or at least non-silver) finish on the entire bellhousings.

Hi Wayne,

Is this the photo you're thinking of? I think I copied it from a post by one of the two gents you mentioned.

[Cecil L.]

Re: 396 403 bell housing-any distinguishing features ???

Cecil------


Yes, you're right. It must have been some other right hand drive chassis application that used the passenger side boss for clutch fork ball stud. The thing is I can't recall any other application besides Chevy II that used a bellhousing-mounted clutch fork ball stud, either conventional left hand drive or right hand drive. There must have been some, though.

Maybe truck. As I recall some of the 60-66 trucks used a hydraulic clutch and maybe the slave cyl mounted on the pass side.

[Wayne M.]

Re: 396 403 bell housing-any distinguishing features ???

Joe -- Here's a few shots of the "383" bellhousing that's on my early '65 L76 (014xx). Don't know if its original to the car, but there have been other reports of this casting # on '65s. The '65 TIM&JG does not allow for it, though.

[Wayne M.]

Re: 396 403 bell housing-any distinguishing features ???

Hi Wayne,

Is this the photo you're thinking of? I think I copied it from a post by one of the two gents you mentioned.

Joe -- Yes, that's it (I copied it this time). Looks like they masked the flat end where the trans bolts on, but everything else got spritzed.

[Joe L.]

Re: 396 403 bell housing-any distinguishing features ???

Joe -- Here's a few shots of the "383" bellhousing that's on my early '65 L76 (014xx). Don't know if its original to the car, but there have been other reports of this casting # on '65s. The '65 TIM&JG does not allow for it, though.

Wayne------


I would expect that it's original to the car. There's absolutely no reason why a 3840383 could not have been originally installed on any 1964-68 Corvette small block or 1965 big block.

[Wayne M.]

Re: 396 403 bell housing-any distinguishing features ???

..... I have seen a few variations of this (403) bellhousing. Some have a cross shaft boss only on the driver side. Some have a clutch cross shaft boss on BOTH sides (neither boss was ever used for a Corvette application). Some have a drilled and tapped driver side boss, some don't. Those with bosses on both sides usually have the driver side drilled and tapped but the passenger side not drilled and tapped. I've never seen one with bosses on both sides with neither drilled and tapped but they may exist. I've never seen one with a passenger side only boss but they may exist.

In any event, I believe the 1965 L-78 used a 403 with a driver side only boss which was drilled and tapped. However, some may not have had the boss drilled and tapped. I don't know, for sure.

Also, it's possible that some 1965 '403's' had an untapped boss on the passenger side. I believe the right side boss was added for right hand drive 1966 Chevy II's but I suppose it's possible the '403' with the right side boss was in production prior to the 1966 model year.

Here's a couple of shots of the 403 B-H on my L78, showing the drilled clutch bosses on both driver and passenger side. Both have the sleeve that Bill W. mentions, but neither are tapped [I just checked].