Re: More Power
no matter what approach you take you are still gunna spend thousands of dollars to build an engine that makes 400 hp.
your best bet is to research your engine and find out what parts you can change to make the most power gains for the dollar spent.
in most cases with the 302 or 351 you will find that the cam can be a major power adder but it has to be complimented with a free flowing exhaust and good high flow intake.
if you really want to make serious power you can bolt on aftermarket heads with bigger valves and then a cam.
you can make as much as 140 hp with a cam change if the rest of your engine can flow the required amount of fuel/air.
i would rather push my Ford than drive your Chevy !