I'm not arguing with anyone, just spouting so take it for what it's worth. I still think a big fat motor isn't going to see much boost out of that blower, and for sure no where near the rated boost. It for me would be easier to just leave the line at the rpm it would hold. I'm thinking very low rpms since the big block isn't going to be as peaky as the small block, so put a glide in it leave as high as it will take, maybe 3000 or lower rpm and the power would be pretty even coming on, and for sure not as much Tq loss at the shift. Like I said if it were a real big huffer then the 400 would for sure be as big as it would ever need.