How to get 400 hp out of 1971 340 .30 over

It was this place I called. Read good things about his carbs. But his wife (I think) kept trying to steer me towards efi and for some reason wouldn’t just transfer me to talk to him.
She was kind enough but wasn’t helpful when I told her I wanted something more modern in carbs.
I’ve used Allstate for several different carb rebuilding kits and those two are great to deal with and knowledgeable.

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