1955 guys?

[Roy B.]

I know this might be asking only two people here having a 55 but which is the 55 Corvette manifold.? And here is the two exshaust heat risers one first design and second design . Any comments

[Ray G.]

Re: 1955 guys?

Hello Roy;
Have one of each manifold.
They both seem to have the same casting number 3704781.
The non-indent manifold could be 3704791.

So, what is what?
Ray

[John S.]

Re: 1955 guys?

ray, do you have a date code on either of the manifolds?

[Ray G.]

Re: 1955 guys?

ray, do you have a date code on either of the manifolds?

Hello John;
Check and get back to you.

[Ray G.]

Re: 1955 guys?

ray, do you have a date code on either of the manifolds?

Hello John & Roy;

No date code(s) I can find.

The "indent" manifold reads "GM2" below the casting #. There is also a "2" on the inside facing the cylinder case.

The non-indent manifold reads "GM1".

These manifold have little corrosion. Possible casting dates were not cast on these manifolds?

Will check for second design also.
Ray

[Roy B.]

Re: 1955 guys?

Ray ! John and I are trying to get a consensus on them but again two 55 owner here? I see you don't list having a 55 ?
I see restored 55's listed for sale now and then having many parts under the hood being wrong because so few people know anything about a 55 . The JM is a joke when talking 55. I don't think it will ever get done because there is little interest and so few 55's are left. Most everything is known about a 53 and 54 but a 55 . My thinking is that early 55 used the first pic. (no de-tent) but that's just a guess.
PS: notice no response yet??? just YOU!

[Robert J.]

Re: 1955 guys?

Hi Roy. My early 55 has the first type of heat riser xxxxx12 and the smooth casting on the manifold Bob

[John F.]

Re: 1955 guys?

Roy, Isent you pics of the manifolds on my stock 55 Bel Air on the other forum.

John F

[Roy B.]

Re: 1955 guys?

I saw it and again thanks

[John H.]

Re: 1955 guys?

Colvin's "Corvette by the Numbers" book shows the 3704791 manifold with the depressed horizontal groove being pointed out in the photo as a Flint (Saginaw) casting, and the one without the groove (same casting number) as a Tonawanda casting.

That would preclude the one without the groove from being original to a Corvette engine, as Tonawanda didn't build Corvette engines.

[Roy B.]

Re: 1955 guys?

So it seems to be the manifold having the grove is 55 Corvette ! We agree?

[John S.]

Re: 1955 guys?

john, roy has shown you two flint manifolds . the manifolds are ribbed and non ribbed . neither are date coded, but all tonawanda have date codes. in corvette by the numbers you will find a non ribbed tonawanda manifold date coded E 2 55. email me at scopeli@comcast.net and i will send a picture of a ribbed tonawanda manifold date coded E 25 55. i have other ribbed tonawanda manifolds, but i am trying show when a design change might have occurred. on the 55 corvette the generator ends up being very close to the exhaust manifold. the ribbed style allows more room. listed in the judging manual is also the second design #3837069. all of these appear to be ribbed from flint and tonawanda. ribbed tonawanda examples that i have examples of are date coded J 14 55 and K 21 55.

[John S.]

Re: 1955 guys?

robert, on the tombstone heat riser, first design part #3713331 with counterweight #3713335. replaced by second design part #3721509 with counterweight #3721512. (2nd design replaced 3713331 on july 1 1955). later the replacement is #3725981 (1956) square counterweight design.

[Cecil L.]

Re: 1955 guys?

Wouldn't it seem likely that the notch is for power steering pump clearance?

[Roy B.]

Re: 1955 guys?

Wouldn't it seem likely that the notch is for power steering pump clearance?

No! I Think is was to straighten that area and has nothing to do with PS or clearance for the generator