More 840 head questions...

[Chevy454]

Well, I got the heads back from the machine shop, and I see what they are saying...they are definitely untouched, and came with the 1.88s.

But, I found something else interesting laying on the shelf in our shop: a 291 head cast just 3 days after (F 10 9) one of the 840 heads that have me stumped! What's interesting is that they also have the 2.19/1.88s, BUT take the peanut style spark plug where as the 840s with the 2.19/1.88s take the N style spark plugs. So, these heads were near the first and last respectively of their type cast...neat, huh!?

Now, more questions: I need to know what the rest of the things cast into the heads mean...like "GM3T", "CONV 4", "NO-5", etc.

Also, anyone know Alan Colvin's phone #?!