I have a set of C8VE heads, I just finished porting following the Mad Porters instructions, turned out well, when I got the heads they were fitted with 2.25 intakes and 1.76 exhausts. the valves that are in the heads are of unknown origin I'm thinking they're Ebay specials. now that the porting is finished they're off to the machine shop, and new valves, I remember a while back reading something here about the best flowing valves for this application, but can't find that thread. Looking for recommendations on specific valves and also advice regarding back cutting if any. Thanks