AFR and most head mfrs would probably tell you these are too small for your application. AFR suggests 180 runners for 327-350 small blocks and 195 for 383-400 motors, but for street motors. You might be able to get by if the heads are heavily ported. I think they will run out of air on top end. I am running a set of 180 AFRs on a 406 but only because they were on a 355 and my car totalled in a fire. Check out AFR's website. I found their tech line very good. Great heads. Good luck. Mep