434 Heads?

[sixty9vette]

Anyone know of this casting, and if they can be improved? I'm looking at some with the larger valves (2.02/1.60). The original combustion chambers were 60cc, but these have been worked and unshrouded and are now 64cc. The intake runners I think are 160cc, and that's what I need to know about. Can they be ported enough to improve the flow? Tnx.

 

[curtis]

434 heads were used 75-79 on 262/267/305. I also would like to know flo numbers on these as well as other stock GM heads. Hope somebody knows where to find this info.

 

[Jack]

I'd be a bit leary of any production heads newer than 1976 that have been surfaced (cut) or may need surfacing ... beginning late 76 early 77 chevy began light weight head castings with a different angle in the decks water passages... when resurfaced their profile around head gasket water passages can change drastically ... leading to inability to seal at head gasket. I think you might find a graphic on this at Cortico gasket company.
JACK:gap