Ford 5000 head gasket, aftermarket not correct?

Was reading thru a shop manual for Ford 5000 and 7000. There was a section on head gaskets. Seams like the 7000 has about 1mm thicker head gasket than the later 5000 engine. But when I was browsing thru head gasket I noticed that aftermarket head gaskets are the same for 5000 and 7000. This leads me to belive that the aftermarket head gasket is made to the thicker specs that the 7000 uses, due to not cause any damage to engine when installed on a 7000. If this is true the 5000 would suffer a compression loss due to the thicker gasket.

Maybe this is my problem, as the sleeves and pistions looked great when I had it open. Also I have lapped all valves so it shouldnt be leaking there.

So has anyone else discovered this? And would my assumption be correct that the aftermarket head gaskets are made wrong? Is a stock Ford gasket avilliable still???

Cyl vol = 1046,5cc

30 bar -> compression vol =36,087cc
25 bar -> compression vol = 43,605cc

Diff compression vol = 7,518cc

Diff in height of compression vol = 0,766 mm (based on a bore = 111,76mm 4.4")

So it would seam that if the gasket indeed are made to the 7000 specs, like I think. Then this would mean a loss of at least 5 bar of compression. Going to try and messure the compressed gasket thickness later today. But as the book states it, the 7000 gaskets should be around 1mm thicker. Will have to check the exact diff.

And if they make the gasket to fit both the 5000 and 7000 one would have to assume its made to the thickness of the 7000 as otherwise when installed on the 7000 it would cause big problems.

Looks like a new head gasket and it will be back to good.

What I wonder is that I see almost every aftermarket gasket for the later 5000 which I have also is also used on the 7000. And according to my book the 7000 gasket is 1mm thicker. My assumption is that the aftermarket gaskets for the later 5000 is made the the thickness spec of the 7000, not the 5000. Due to this a aftermarket gasket would result in a compression loss, which I currently have as I have too low compression but equal over all cylinders. If the rings would be the problem my assumption is that it wouldnt be so equal compression over all cylinders.

Cause if they made the gasket to the 5000 thickness problems would occur when installed on 7000 engines.

I will get a stock ford 5000 gaskets from the NH dealer and try that. I just wanted to know if someone else has noticed this....

I could be wrong about this.... but, I can't really see that 1mm really making much difference. If you're measuring the compressed thickness of an old gasket to the non compressed thickness of a new gasket, then you just found the difference. If 2 new gaskets are still 1mm apart though, I still don't think I'd worry about it. If the engine is lacking compression to the point where it will not start, or isn't producing much power, it's probably going to be something a good deal more serious than the head gasket, unless the gasket is leaking. I can't imagine that a change in gasket thickness of that amount would alter compression pressure more than a few PSI... or a few millibar. HTH.

Rod