on the wallace site the report on flow for the the good #16 heads are right up there in flow with the #48. I have the good #16 heads and they take the bigblock 7/16 chevy rocker studs , screw right in. then just pick up some SS valves a good set of springs , keepers and rockers and they breathe very well!

I got mine for 300 from a guy who tried running them on his 455, found compression to high and took them off. They were sitting on the floor of his garage he was going to toss them. i saw the 16 and screw in studs offered him 300. he grabbed it . all together with parts and machining plus pocket porting. i have about 1000 in the heads. id like to find another pair.