Stock 75 heads, I think they are J castings
Mike installed the larger valves in them and I'm sure he massaged them some aswell, but you would have to check with him for details on that
Can I ask what Dyno this was tested on? Not that I doubt you but the #'s sound high to me. Was there anything else done? what intake? comp? Maybe I am just missing something. sorry no trying to be rude. Have been gathering parts for 408 for a bit now,open intake bowls & gasket matched EQ's, [email protected] .560" roller, modified mopar EFI, big injectors and 1000 cfm TB and my stuff pencils out at 470 HP 475 TQ, I would think there would be a bigger difference or are my numbers low? I cant find any dyno sheets from FI 408 except for chassis dyno w Dakotas. I have built a few of these but never got any dyno time as it was in Portland or Sacramento. They are stupid fast though, guess I need to buy some dyno time now Medford has one:)
