383 gasser engine build???

that is a flat tappet cam... But a hydraulic so he can use stock arms... If it was me, I would try to dig up something like the 270H Comp. With 452s on a 383 you'll need something that is not too large in terms of overlap but still sounds sizable. I think the 284 with the tunnel ram and compression around 9:1 might be too much. I'd also say mill the heck out of those heads and don't forget the milling of the intake if needed to fit it.