Buddy bought the biggest horse kit, somewhere around 500 i think, very disappointed, small block chevy. Different guy bought trick flow r series heads for his 393 stroker, (ford 351), has had heads on for bout year and theres a hole in them now that leaks antifreeze, BUT.......everybody has different stories. Have you checked out holley systemax systems?? or dart top end kits?? just my 2 cents.