Inline six parts interchange

[Truckbert-CS]

Does anyone know if the intake and exhaust manifold from a 250 will work on a 292?

Some of the GM truck 250s had a two barrel intake, and I have a chance to pick one up.

What do you think?

TW

[garmar]

I'm pretty sure my Dad did this with a 73 Chevy with a 250 I-6 he had. I also did a search and the manifolds show up as the same for the 230, 250, and 292.

Also, Pre-75 intake and exhaust manifolds are two separate pieces. After that they were made one piece. Do your manifolds unbolt or are they cast with the head?

[Truckbert-CS]

The one I saw was the separate exhaust and intake. I did some more searching and the intakes do show up like you say.

I was really interested in the exhaust because it was a 2 piece manifold. I'll check again tomorrow and pull them off if this is the case.

I just bought a 292 last week and am looking for options to dress it up a little.


TW

[raycow]

AFAIK, no GM inline engines had the intake and exhaust manifolds cast as one piece. Some 75-up engines had the intake cast in one piece with the head, but the exhaust manifold on those was still a separate casting. I do not think the exhaust manifolds from the two different types of heads will swap, but I haven't actually tried it to find out.

250 and 292 manifolds (intake or exhaust or both) will definitely swap if both engines have the same type of head.

Ray

[GRX]

You are thinking of the "integral head". Avoid these at all costs.

[garmar]

Originally Posted by raycow

AFAIK, no GM inline engines had the intake and exhaust manifolds cast as one piece. Some 75-up engines had the intake cast in one piece with the head, but the exhaust manifold on those was still a separate casting. I do not think the exhaust manifolds from the two different types of heads will swap, but I haven't actually tried it to find out.

250 and 292 manifolds (intake or exhaust or both) will definitely swap if both engines have the same type of head.

Ray

Exactly right. I meant to type the head and intake was cast together not the intake and exhaust. Sorry about the mistypo.

And yeah, they're junk. My Dad had to replace it on an old 75 Chevy he used to have with the pre-75 head and intake that wasn't integrated. It cracked IIRC.

[MudBug]

250 and 292 share the same dress up stuff except for the side covers.292 has a taller side cover but you can get 292 specific covers.

[Mr79C10]

Originally Posted by GRX

You are thinking of the "integral head". Avoid these at all costs.

I have this.
And it just sux, Cant do anything to it. Besides maybe paint it.

[raycow]

Originally Posted by Mr79C10

I have this.
And it just sux, Cant do anything to it. Besides maybe paint it.

Just in case you didn't know.......
If you are having problems with one of those, it can be replaced with the earlier type head. No modifications are required other than linkage.

Ray

[GRX]

Originally Posted by raycow

Just in case you didn't know.......
If you are having problems with one of those, it can be replaced with the earlier type head. No modifications are required other than linkage.

Ray

That and new manifolds of course. Did the conversion on my friend's work van several years back. Did I mention what an absolute bear it was to remove one of those monstrosities from a van? Yes, believe I did.

Have to chock that wonderful integral head to misguided cost saving attempts of the late 70's to early 80's. Most every one which came into my shop back then was cracked. And if not they certainly needed to be resurfaced.

[Twisted6]

You would be much better off in the long run to go pre75 head.Better intakes Even if you make your own like i did.And you can have a much better exhaust system as well.You can get the pre75 heads to breath better then 240 cfm.You can't do much with the 75&newer junk Ops i mean head LOL.

[Truckbert-CS]

OK, after a closer look it was the integral head (Intake and head cast together.)

So I left it in the salvage yard. I found a few other misc. parts so the trip was not a total waste of time.

Still looking and learning....

[ricaltman]

Originally Posted by GRX

That and new manifolds of course. Did the conversion on my friend's work van several years back. Did I mention what an absolute bear it was to remove one of those monstrosities from a van? Yes, believe I did.

Have to chock that wonderful integral head to misguided cost saving attempts of the late 70's to early 80's. Most every one which came into my shop back then was cracked. And if not they certainly needed to be resurfaced.

What were the symptoms of a cracked integrated head and where were the cracks?

[GRX]

Originally Posted by ricaltman

What were the symptoms of a cracked integrated head and where were the cracks?

Worked with a lot of these for fleet service. Always acquired new head from GM since all used heads from the yards would be cracked. Typically external around the exhaust & intake areas. Easily visible. Need not magnaflux to see them. Cracks in the exhaust seat areas were fairly common too.

[ricaltman]

Originally Posted by GRX

Worked with a lot of these for fleet service. Always acquired new head from GM since all used heads from the yards would be cracked. Typically external around the exhaust & intake areas. Easily visible. Need not magnaflux to see them. Cracks in the exhaust seat areas were fairly common too.

Thank you. I cannot get this thing to idle. I've changed everything in the electrical/distributor/fuel systems including carb. All except fuel pump. I'm lost.