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Discussion Starter #1
Hey all,
I have a '66 T100SR, with an E3991 head. It's got a couple chipped fins, as well as a heli coil in one of the spark plug holes, so I jumped at the chance to pick up another one at a swap meet this past weekend.

My old head has the "E3991", "AM", and "Y1" stamps, as well as a serial number. The new head has the E3991, Y1 and serial stamps in the same place, but it is missing the circular "AM" stamp. It also has an extended head gasket mating surface near the intake ports, and instead of having two stud holes per intake port like the old head, this one has four stud holes per port.

Aside from these differences, the heads look completely identical, and appear as though they might be interchangeable. The new head was advertised as a "68 TR1" head as well.

Any idea if I might be able to use the new one with my old 500 motor? It sure looks a lot better.

-BM
 

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Discussion Starter #3
Brought both heads to the local machine shop yesterday, and upon closer inspection they appear to be identical in size (ports, etc.) So, I left the "newer" one to be done up.

It would seem as though someone had modified at least the studs, but the extended gasket mating surface seemed like it was cast with the rest of the head.

I forgot to take pictures before I dropped them off, but I will be sure to post them once I get them back, for future reference.

Thanks,

-BM
 
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