[pjdutton]

I have been given a set of 71 No94 heads.Other than worn valve seats they are fine.I am thinking of fitting bigger inlet and exhaust valves(2.11"+1.77").The studs were push in that have been removed so I think I can install BBC rocker studs.If I have 0.040" taken off head surface what sort of compression ratio can I expect from a 0.030" over 400?I am in the UK so you can imagine how hard it is to get decent parts for these engines.

[RicksGTO]

I have a set of #94's with the larger valves installed and some ARP screw in studs. I CC'ed 2 or 3 of the chambers and they both measured right at 87cc's. You never know till you measure but the stock chamber size is supposed to be 90cc's. They should be around 8.6 to 1 if they are at 90cc's and you have a .030 over 400 with everything else relatively stock so milling them .040 would knock 8 cc's off of that and bring it to a little over 9 to 1. Just be sure and measure everything to be sure what compression you have. You would need to have the intake side of the head milled .040 as well to keep your intake fitting right.

[pjdutton]

Thanks for reply .I had not considered the milling of the inlet face.