#46 Pontiac head

[skierkaj]

Can someone help identify this head?

#46 Pontiac, date code A029, D ports, small valves (1.96/1.66)

I've deduced via the casting number and date code that it is a '69 400 or 428 head, but I'm a little puzzled on the chamber size. It has the small valves (1.96/1.66), D port, so it lines up with either a:

400 cu in, 290 HP, 68 cc chamber w/10:1 comp.

428 cu in, 360 HP, ???? cc chamber w/10:1 comp.


What is the chamber size on the 428? The same as the 400, or is it a 72 cc chamber? It's one or the other, but which one?

Found the heads at the Jefferson swap meet. Got a good price on 'em, and couldn't resist.

An interesting thing about the heads are that they are missing a tapped bolt hole on each end of the head for the exhaust manifolds. I can't figure out why this is. They could be drilled and tapped, but why weren't they from the start?