using a later head on an eariler motor

[austinsailor]

I know you can use the later head gasket (with the extra hole) on the earlier motor. Can you use the later head and head gasket on the earlier motor? It'll block off that extra water hole, but will it hurt anything?

Has anyone actually done it?

[michael.warshaw]

my motor p15 218 had a 54 dated head, and many motors similar to mine had the same thing done aswell, i wonder why they changed?

[Reg Evans]

Well.......a 52 230 has a cr of about 7 to 1 whereas in 59 it was raised to 8 to 1. Both heads are for the internal bypass system.

[Flat belt]

I don't what year they changed but I believe there is an extra water passage on the later ones. You can see the bump on the very front of the head for the passage. I learned this about 1970 when I put an earlier head on a late block. Water everywhere. Someone must know more about this than me.

[Reg Evans]

That's why I compared a 52 head to a 59. By then they were all internal bypass If my memory is serving me correctly right now.....however it is Friday afternoon and I've been clocked out for a while now.

[austinsailor]

I understand that '51 started the extra hole. My '51 Fargo 228 has the extra hole, my earlier 251 mystery motor I'm rebuilding does not. Fargo has a smaller combustion chamber, so it'll be higher compression compared to the original 251 head for the same amount of milling. Only question is, can I use the later head on the earlier block, I think the answer is yes, using the later gasket. Correct?

[hkestes41]

I am running a 53 head on my original 48 block, bumped compression from 6.6:1 to 7.1:1. No problems with the install or cooling.