Repro 3899621 Bell Housing

[Jack O.]

I see there are a lot of reproduction 3899621 bell housings available. Are these good reporductions or should I try to find an original? Anyone know anything about who makes the repro's and where?
Thanks,
Jack

[Joe L.]

Re: Repro 3899621 Bell Housing

I see there are a lot of reproduction 3899621 bell housings available. Are these good reporductions or should I try to find an original? Anyone know anything about who makes the repro's and where?
Thanks,
Jack

Jack------


The reproductions I have seen appeared excellent to me. Some of them might have a bolt hole in the middle upper which the originals did not have. However, some are just like the originals with no center, upper hole.

On the other hand, good used originals are really not that hard to find.

[Alan D.]

Re: Repro 3899621 Bell Housing

Small question, is it for your 69? If for a 64 you really need the 383 one, the 621 came out latter, so double check (Yes for JG it was OK the last time I looked)

[John M.]

Re: Repro 3899621 Bell Housing

A friend of mine bought one of these and we had to install the cam shaped alignment pins in the block to properly align it for the transmission/ pilot bearing. PIA. Get a real one if you can.
JB

[Larry M.]

Re: Repro 3899621 Bell Housing

A friend of mine bought one of these and we had to install the cam shaped alignment pins in the block to properly align it for the transmission/ pilot bearing. PIA. Get a real one if you can.
JB

To avoid issues, anytime you change or replace bell housings on your engine it is a good idea to mount a dial indicator and check for overall alignment.

Larry

[Gene M.]

Re: Repro 3899621 Bell Housing

I always thought about the bell housing alignment. If one figures the holes in the housing are the datum and the center hole is machined to +/- .005" location tolerance and the holes for the pins in the block is also +/- .005" there could be a .010" out of nominal position. And even more in quarenent tolerance (.014") as the long side or triangle hypotenuse is longer. In the 60's a tolerance of +/- .005" was fairly tight. A possible assembly of .010" to .014" out of position will destroy the front transmission bearing. It may take a couple thousand miles but eventually will happen. I have seen normal production vary about .008" out and still assemble and run ok. But I know it is not a good thing. Those Muncies are fairly forgiving.......... good design.

[Michael G.]

Re: Repro 3899621 Bell Housing

Get a real one if you can.
JB

I've heard the same thing. Nothing like original parts......they fit and function to higher degree.

[Jack O.]

Re: Repro 3899621 Bell Housing

Thanks everyone for your inputs. I'm going to go with an original or fix my original if possible. I also noticed that the repro's are a much rougher casting - at least it appears that way from the pictures I've seen.
Jack

[Tom P.]

Re: Repro 3899621 Bell Housing

I don't know how many different vendors make the 621 repo, but if you talk to Kiesler, they swear straight up and down and sidways that THEIR 621 housing is on the money and the others are inferior.
As far as installing and using a 621 housing, I have no personal experience with any of the repos because all of my 621s are original GM.
As far as appearance goes, if you are familiar with an original GM cast 621, the the repos are immediately distinguishable from originals.
As mentioned above, I agree with searching for an original GM 621. They have become a little scarce in the past few years, consequently they have also become somewhat pricy.
Oh ya, and NEVER, NEVER, NEVER tell a seller that you need a 621 for a Corvette. Corvette parts that are also common to other Chevys always have the price jacked up. Tell the seller you need it for any Chevy other than a Vette.