My Street Hemi - original carbs, intake, springs - takes noticeably more pedal pressure than say a stock 383 car, but I wouldn't say excessive. Same pressure running/driving as not. I can feel when each of the 4 stages open, which is common to every Street Hemi I've driven.
Only thing I can think of on yours is maybe some binding that's aggravated by heat - which would be odd - or your butterflies are somehow closing over-center - which I don't should be possible - or too tightly.