Update: Thanks to all the guys who expressed an interest. From the information I got from NHRA, let me explain what I think I will do. The Magnum R/T head must match the LA head for whatever combo a racer claims. The heads I have are 2.02 1.60 with 180 runners and 8mm valve stem size. I have two sets; one ported by Ray Barton and one by McDowell and both have ported Mopar M1 manifold. We only ran the Barton heads which went 9.80 in Top Stock @ 2980 lbs. Duster body, 9 in tires, good driveline pieces, .525 cam with modified factory roller tappets, Comp Cam rockers, single 750. To qualify for SS, I will have to bring the valves to 3/8 stem, 1.88 if I claim 360 etc, and 2.02 as a 340 and get the runners to 163 and 72. The R/T heads also oil through the pushrods, but no problem. We got good ones with a little smaller hole and no problem. I will probably take the Duster and fix the heads and run as a 340 in SS, or a 360 in GT. Maybe I can save someone some trouble and time before I sell anything to make sure they are as good as I think they are. According to NHRA, the 396 Edlebrock/GM head and the Ford 428/Shelby/Edlebrock and any other allowed replacement head were required to do the same thing. The 360 motor with these heads made 560 hp. We found more later, but by that time we had Edlebrock heads, learned more in intakes, valve train etc. Call me or email me for more info. Jeff
jefft@southlanddodge.com 888-876-1817 Tell the operator it concerns racing. Thanks