I've personally built 3 different 302 where where dyno'd at over 400hp (broke in on an engine dyno) with one touching 468hp and non of them were FI or had NO2 (only baby's are bottle fed). Remember the displacement factor, they have about 70% more displacement then a 7m.
It will take internal work and a different set of heads to make good power and yes the stock oilpump shaft and junk but thats an easy fix.
There is also plenty of cheap off the shelf stroker kit availible too. With a 347cid stroker kit, right cam and heads and a good set of headers and exhaust, 500hp is not hard to achieve.
The biggest problem I see with it is the "wanting" a 50/50 weight balance. The already heavier 302 is not going to help it, hence my reason for sugesting a UZ or an LS engine in my previous post due to them being aluminum block engines.... I can tell you this, the UZ is quite a bit lighter then a 7M and im pretty sure the LS is even lighter then the UZ.