Hello, Folks,

(1) I notice that the Corvette vendors list different part numbers for a 63 327 bell housing and a 64-67 327 bell housing - do they interchange? Is there any difference in their dimensions, or is it just a matter of the parts being 'correct' ?

(2) I'm trying to determine if my bell housing is an original (I have an early 63 - 103XXX) - can anyone provide the part number?

(3) Is the clutch fork ball stud the same for all 63-67 Corvette applications?

EDIT: Removed the transmission today. The ball stud I have on my 403 bellhousing measures 1-3/8" from end to end. My understanding is that all 63-67 Corvettes use a 1-1/2" ball stud.
Is mine within tolerances, or do I have the wrong ball stud?


Thanks in advance.

 

The front bearing retainer on '63 Corvette manual transmissions was smaller in diameter in 1963 than prior or succeeding years. This goes for both the BW and Muncie. The bearing retainer size is what determines which bellhousing you need.

The front bearing retainer is what slides into the bellhousing and centers the transmission.

I don't know the numbers offhand.

 

From Adams Tech Guide:
'63 bellhousing part# 3788419 casting# 3788421
'64 bellhousing part#????? casting# 3858403

Maybe the difference is due to the changeover from the T-10 to the Muncie? Yep, that was it, read a little further and the bellhousing casting number changed withe the change to the different trans. I'll bet either can be used but if you have a T-10, get the early bellhousing for judging purposes.

Might try calling and asking, most vendors are fairly knowledgeable.

 

You need to do some more research.

 

Here is some info that may help ===> Click Here

George

 

Good stuff. Pretty much what I have here on the Bellhousings.

 

ALL 63's used the small-hole 421 bellhousing, whether they were early cars with a T-10 or later cars with a Muncie; both transmissions had the one-year-only small front bearing retainer and required the matching 421 bellhousing. Starting in '64, the Muncie got the larger front bearing retainer, and used the 403 bellhousing with the larger hole.

Midyears (and all Corvettes from '57-'81) used the #3729000 pivot stud (1-1/2").

 

^That is correct.
I do not know, no one has given me a good reason, or even a half @$$ reason as to why the 63 ONLY bell housings got the smaller hole.
The 55-62 and 64-later bell housings ALLLLLLLLLLLLLLLLLL had the same size hole in the bell housing, but that 63 housing is a b@$!@rd housing!!! Thus, the 63 ONLY trannys also had the smaller front bearing retainer.
BUT WAIT---------------------there is an exception to EVERY rule (surely you knew this was coming).
The 63 409 pass cars retained the open bottom housing that was used in 61-62 Corvettes and Hi-perf 61-62 348-409 engines (ALLLLLLLLLLLLLLLL other 63 bell housings were the full enclosure version). These open bottom alum housings (as best as we have been able to determine) were unique ONLY to the 63 409 pass cars, which means they also got the BIG, 14in diameter, 168 teeth flywheels.
Beginning with 63, ALLLLLLLLLLLLLLLLLLLLLLLLL 63-65 Corvettes got the smaller 153 teeth flywheels, thus they all had the smaller bell housing (421 in 63 only, then 383 and 403 for 64-later). Corvettes DID NOT get a big flywheel/bell housing again until the 1966 427 cars.
I do not have the main case casting number for the 63 T-10, but the 63 Muncie main case casting number was 3831704. Again, this was a one year only (63) Muncie main case.
If you CANNOT find a 421 housing, or a 704 Muncie main case, or just one and not the other, you can put a 63 together simply by using a 383 or 403 housing (AS BEST AS I CAN DETERMINE, the 383 and 403 housings are identical) and 64-5 Muncie with the 3851325 main case. NOT CORRECT for 63, but it will all bolt together and it will work.
OK, fine, but what do you do is you have a correct 63 704 Muncie main case, but you can't come up with a 421 housing (small hole)? Well, there is an easy fix. It's the same thing that was done on the 63 4sp 409 cars. Locate an early junk 3sp and pull the front bearing retainer off of it. It will need to be a retainer with the 3741458 casting number. This is the front bearing retainer which was also used on the 63 only 4sp trannys to mate them up to the bell housings with a big (standard size as I call it) hole. Toooooooooooooooooooooo easy.
You can ONLY go one way with this. That is, you can adapt a 63 4sp tranny that normally used the small front bearing retainer to fit a big hole housing, but you CANNOT adapt a small hole housing (421 housing) to work with a later 4sp that had the big (standard size) bearing retainer.

 

DZ:

What size flywheel did the '64 300 hp. cars have?

DH

 

Dan,
From the very beginning of the Chevy V8 engine (introduced in 55), there have only been TWO sizes of flywheels:
Big-14in diameter, 168 teeth
Small-13in diameter (acutally about 12 3/4in), 153 teeth.

From 55 to 62, ALLLLLLLLLLLLLLLLLLLLLLL Chevy V8 flywheels were ONLY the big version. Thus, up through 62, ALLLLLLLLLLLLLLLLLLLLL bell housings were ONLY for the big flywheel.
The small flywheel was first introduced in 63, thus the first small bell housing was in 63.
ALLLLLLLLLLLLLLLLLLLLL 63-65 Corvettes (INCLUDING the 425hp/396 in 65) got the small flywheel. The ONLY engines to get big flywheels in 63-later Chevy products were the pass cars and trucks (but actually, the trucks kept the iron open bottom version until about 70. Consequently, ANY 63-65 BIG alum bell housing brings a VERY PREMIUM price.
The 63 small alum housing (421) in my opinion is ONLY valuable as a correct restoration part. I have ZERO desire to own one.
BUT, on the other hand, I'd love to have a couple dozen 63-65 big housings to supplement my retirement fund!

The housing on the left is the 60-62 alum open bottom version (used on ALL Vettes and 60-62 pass cars with Hi-perf 348/409) . There is a 60 only, and a 61-62. The difference between the 60 and 61-2 is the size of the opening for the throwout bearing fork. The 61-62 housing was used on 63 409 pass cars.


The 64-65 BIG housing was fairly rare, and was ONLY used on pass cars and the 65 Chevelle with the 396 (Z-16 car, 201 built). This housing was NEVER used on 64-5 Vettes, because they DID NOT get the big flywheel!

 

Thanks to all who have replied to this thread. I now have the information I need.

Continuing in the grand tradition of my 63 Corvette mutt, looks like I have the later 64-up 403 bell housing, which goes well with my 64 Corvette clutch linkage and the 1969 Oldsmobile 442 Muncie 4-speed!

After I drop the tranny, I'll verify that the clutch fork ball stud is indeed the correct #3729000.

 

I just finished removing the transmission and clutch (was actually easier than I thought).

The ball stud I have measures 1-3/8" from end to end. Is this within tolerances, or do I have the wrong ball stud?

Thanks again to all.

 

1 3/8 was the original size but it has been discontinued and superceeded with the 1 1/2 ball stud. The General says the longer one is the standard and acceptable replacement for the discontunued part.

 

You want a reason? Try this one.

The first edition of the aluminum bellhousing and small flywheel first appeared, not on '63 Corvette or Pass car, but on the '62 Chevy II 4/6 cylinder engines. They used the small bearing retainer on the transmission and the 154 tooth flywheel.

Exactly what the differences between the Chevy II housing and the pass car/Corvette, I can't tell you but I can tell you the Chevy II bellhousing appears it would be a functional substitute for either of those '63 pass car or Corvette applications.

The Chevy II bellhousing was changed for '64 to the larger bearing retainer size.

 

As I recall, the Chevy II bellhousing had the hole for the fork down lower, and the fork exited the bellhousing at a downward angle vs. horizontal on pass. cars and Corvettes. I think.

 

That's correct for the V-8 bellhousing. The fork angled down about 7:00 so the adjustment rod would drop below the V-8 oil filter which you probably will recall was the first "shorty" V-8 filter that Chevy used.

The '62-'67 4/6 cylinder clutch linkage stayed the same through the production run. The 4/6 cylinder fork came straight out the side. For example, the '64 4/6 cylinder housing (3840383) is the same as lots of Chevelle, Camaro, Nova, some pass car though the late '60's and Corvette '64 up to ?

My guess is Chevrolet tried to commonize the bellhousings and/or machining and that small bearing retainer didn't work out on the larger engines so they changed them all to the larger bearing retainer for '64, Chevy II included. That's just a guess of course.

 

If you are still in need of solving your bellhousing situation,I may be of some help. I bought an NOS 3788421 bellhousing for my 64 because I was of the understanding that the 421 casting was used thru early 64.If you are interested in a trade, let me know. This housing looks as new as the day it was cast. [email]rlagesse@hartcompanies.com.
thanks,

raylag64

 

Do you still have this bellhousing? If so, what do you want for it? I do have a 403 bellhousing and might be interested in a trade. Currently looking for a 1963 T-10 and have a 64 Muncie.
Thanks!
In2Vette's

 

Immediately after the 63 421 housing, was the 383 housing (64), then the 403 housing (late 64). For all practical purposes, the 383 and 403 are identical and are totally, completely, 100% interchangeable. But as mentioned, the 421 is one year only and will only mate with a 63 T10 or a 63 Muncie --------------UNLESS IT WAS A T10 or MUNCIE USED IN A 63 409 CAR! ALL of the above 3 housings are used ONLY with the smaller, 153 teeth flywheel. In 66, the larger 168 teeth flywheel was used on BB Vettes and the FIRST housing for the big flywheel was the 444. Then in very early 67, the VERY COMMON 621 housing was used up through the 70s. About the mid/late 70s, the 697 housing replaced the 621 as both a production and service replacement housing.

Tom Parsons

 

I just made a spacer to fit around my 1704 case/bearing retainer and inside the oversized hole in the bell housing with an interference fit.

I did post pictures awile back about this mod. I didn't want to mess with the only major component left on the car that was original so I added the spacer to the bell housing.