Hello all; there are somr people on here that now me!!!! Her's my fix fore your problem!!! Has anyone ever look at the deck of a small block chavy??? I believe all big block mopar's and aftermaket iron and aluminum blocks have a cooling hole between were the exhaust passage's are! I drill the head's , iron and aluminum 1/2 inch' to help flow more wate here. I have seen many year's ago at friend's shop were this would torch the head in this area, on iron head's. Hope this help's, good luck!!! OOOO buy the way get ride of that purple shaft and get a real bump shaft!!!!