Tune 4bbl duals small cam gears stall and shift kit, nice basic setup that can do one step at a time. Then the displacement, velocity, cr police come in and confuse the F out of the OP.
Free horsepower is the best horsepower.
A good tune up goes a long way. Advancing base timing,making sure you are getting W.O.T. Making gaskets out of cereal boxes.etc
These are all the steps that lead to real gains and build skills.
In the free performance category,when I got a free super six intake for my slant when I was a kid I couldn't afford the 2bbl specific lockdown linkage so I modified the 1bbl stuff and added a piece from my erector set.
I split and stacked firewood for a carb.