Hi All
I traded some parts for what I thought was a 1957 371 engine. After getting it home and looking at the numbers it appears to be a 1955 324 (engine number starting with a V and 8). One head is a #14 and the other head is a #16. It came out of a boat so it has aluminum exhaust manifolds and it may be a manual transmission flywheel. It's pretty, a lot of bling, but I'm wondering if the heads are similar enough to function correctly. I've removed the valve covers and both heads have the beehive springs, so they look the same. But I've not got it on an engine stand to pull off the oil pan and see how the bottom end looks.

 

What is the casting number on the back of the block? Can't quite make that out from the pictures. Interesting they got '57-58 371 heads to work on a 324 block. I know there are few issues, I was always lead to believe #10 heads from '56 is as far as you could go. I see the screens on the bell housing area, so yeah sure seems like a 324. They plugged those holes later on after they added transmission coolers starting in 1956 with the Jetaway.

After reading this again, someone must have done some machine work already to make 371 heads work on this block. https://www.jalopyjournal.com/forum/...s-work.527003/

 

Go back and read it more carefully. The 57-58 heads are fine, except maybe a port size difference. THE REAL QUESTION was the J-2 INTAKE manifold on a 324.
The J-2 Intake manifold is actually TO WIDE to fit between the heads on a 324. This is due to the change in deck height on a 371 being more than the shorter 324.

 

So if you have 371 heads with an intake it will just bolt up, presumably.

 

So. if you have a 324 manifold, the 371 heads will bolt up, presumably. A 1957 or later intake manifold is too wide to fit between the heads on a 324.

 

There will be a port mismatch unless a '56 324 manifold is used with the 57 heads.1954-55 had smaller intake runners.

Regarding the question of whether #14 and #16 heads will play nice together... I will guess so. I have never seen any documented differences between the heads, but i would be mostly concerned about the combustion chamber volume. Easy to check after the hard work of tearing it apart is done. For what it's worth, I am not sure if different compression ratios were even available in 57-58. 371 heads were apparently prone to cracking, so it's not surprising that the heads don't match. Assuming no dome on the pistons in the 324, or milling of the heads, the compression should be similar ish to stock 1955 oldsmobile... something like 8.5:1... At least that's what I got working backwards with a calculator some time ago. I have a pair of #16 heads on a shelf if you need/want anything measured. Also, use head gaskets that match the heads you're running, not the block. In this case, use 57-58 head gaskets.

Now that you have the valve covers off, double check for other goodies like adjustable rockers. There is always a possibility to find some desirable speed parts in a gussied up old engine like that. Very cool!

 

It looks like stock parts under the valve covers. I've pulled the flywheel and counted the teeth, 145 so I believe it's a 324 flywheel. I was going to pull the marine manifolds off but will need to cut down an Allen wrench to do that. There's not enough room to get a standard sized one in there and I tried vice grips on the outside of the bolts. Didn't budge. The Allen head bolts on the back had some kind of pipe dope on the threads and took a lot to remove as well. I've got plenty of other projects to work on but when I saw this for sale it caught my eye and I was able to work out a trade for some other parts I had. It may go under the work bench for now and I'll play with it at a later date. John