BBC vs SBC do you notice a big difference?

[71400lb]

Just wondering if I'd notice a huge difference or hardly any if I had the 396 (402) big block Chevy in my truck instead of the 400 Small block Chevy I have now?

My SBC is a 400 bored .30 over with a 4 bbl Quadrajet carb, and a Competition Towing cam...the motor is actually out of a 1972 Chevy Nova(and I believe it has the stock heads, whatever they were on 72 400"s in Nova's).
Rest of the line-up includes a T400 3 spd and the H052 rear with 3.73 gears open differential.

Thanks,
Rick
1971 Chevy Cheyenne
C/20 Long Bed