fordracing 65,
First, I'm not a ford guy at all, but you are just missing it. When did nearly 900 normally-aspirated HP become unimpressive? Your 427 sbf does not do that - period, period, period. And you're wrong about the "same output" you tout: 730rwhp/527ci = 1.38 rwhp/ci as compared your 515rwhp/427ci = 1.21 rwhp/ci - you need to do the math!
Besides, straight-up, 730 rwhp is more impressive than 515 rwhp, period...
Speaking of doing the math, we can do other math as well - as far as a total car weight goes, assume the same chassis (1800 lb without engine). Say the SOHC car weighs 2430lb and your sbf car weighs 2200lb (correct 230lb difference for engine weights) 2430lb/730rwhp = 3.33 lb/rwhp vs your 2200lb/515rwhp = 4.27 lb/rwhp. The SOHC car beats your sbf car, even with its lower weight, by 22% in hp to weight... A HUGE advantage.
If you want to talk supercharged, keep it even and supercharge both the little sbf and the SOHC and see what happens... I could do the math and show you, but you get the picture
Barry, this is a very impressive engine you built! Coming from a non-ford guy!