Wrong cylinder head?

[Bianca1973]

Hello everyone,
Question: will a cylinder head from a 1592cc work on a 1608 block? I’ve done a bit of reading here and other places and the answer generally seems to be no… However, I bought a 72 spider a few months ago. I drove it 110 miles home, drove it a few weekends and eventually brought it another 200 plus miles from Redding to San Francisco. Drove it to work a few times over the next two weeks. It had some other issues that led me to remove the head and have it rebuilt. Then I found the head gasket didn’t match 100%, and began to investigate.

The head has 132AB9A and 4277590 cast on top. The block has a circular tag with 125BC000 and 4194206 and 1E stamped onto it.

Am I correct in thinking this is the wrong head? I started looking into it when I found that the head gasket holes did not match, specifically- the gasket did not have corresponding holes for several openings on the head. The other holes matched.
Is it a case of ‘it works, but very poorly’? Because it clearly worked before. The car did have cooling issues, and I found both internal and external thermostats when refreshing the cooling system, which supports the theory that it has the wrong head.

Assuming I’m correct, does anybody on here have a spare 1608 head I can rebuild? I do have a freshly rebuilt 132AB9A I’d be happy to trade…

Thanks for your thoughts.

[18Fiatsandcounting]

Are you sure it's a 1592 head? The 4277590 number matches up to the 1756 head.

As to whether this combination will work? Maybe, for a while, but it's far from ideal. Several issues: 1) the 1438, 1608 and 1592 engines had 80mm cylinder bores, while the 1756 and 1995 engines had 84mm bores, 2) the bore spacing on the 1438 and 1608 blocks is different than that on the 1592, 1756, and 1995 blocks, and 3) the coolant opening in the front of the head is different on the various engine sizes, which can cause coolant leakage into the #1 cylinder over time.

But it sounds like you have a 1608 block and a 1756 head, which might work. You'd need a gasket for the 1608 block, and you'd need to make sure that the coolant and oil passageways line up. You don't need both an internal and external thermostat as I sense you've figured out, although opinions differ on which setup is best.

You mentioned that you're in the San Francisco area. If that's true, I'm out in Livermore, so look me up. I've got several blocks, heads, and a garage of parts. I do have a 1608 bare head, although I was hoping to hang on to it, but I might be convinced otherwise. Plus I tinker with these cars pretty much daily.

-Bryan

[BEEK]

You can put a 1756/ 1592 / 1995 head on a 1438 or a 1608 block. Fiat never changed the bore spacings on the 8 valve heads. If you look at the heads on the 1756 and the 1995, the combustion chambers are offset from bore centerline. The only fitment issue is putting the 1438 / 1608 head on the later blocks, the front coolant passage will barely be covered by the "fire ring" of the head gasket and will fail. Some people have welded up the coolant passage and used the early heads with no issues after that.