Looking for info on 840 cylinder heads

[Joseph E.]

I've got a set of GM 840 cylinder heads on a car that I own and was looking for some information about them. They are rectangular port heads with Hi-Perf cast into them but I was wondering if they are open or closed chamber and what size the intake and exhaust valves would be. Any input would be most appreciated. Thanks.

Joe 45420

[Wayne M.]

Re: Looking for info on 840 cylinder heads

3919840 heads are closed chamber design with stock intake valve diameter of 2.19" and exhaust 1.72".