What will make my 1971 Ford Maverick 302 go faster?

The biggest difference will come from,changing the heads carb,cam and ignition.

It depends how much you want to spend. The best free mods would be turning up the timing a little, unbolting the muffler, and removing interior pieces. Maybe a small nitrous boost.

Next would be, as someone else suggested, getting a newer 5.0 out of a crashed car. And a 8.8 rearend with steeper gears.

And then going the whole built motor route.

How many miles does it have? If it's getting on up there, rebuild the engine. Put flat tops, or domes in it. Put a cam in it. Port the heads.You can do that yourself with a dremel. Invest in a better intake manifold, and a 4bbl carb. Port the intake manifold if it needs it. You don't need mufflers, or cats, so leave them out. Put dual pipes on it. Anything you can do to reduce backpressure, and improve intake efficiency, will build horsepower. Swap gears in the rear-end. Put different sized tires on it. There are literally 1,001 things you can do to build horsepower.

Find a 5.0L HO motor. Fuel injection too complex, remove and sell the parts and put in a 4bbl intake and carb. If your are running drum up front consider swapping to disc. Safety first.

Little things. Take as much weight off of it as possible. Chang the oil, air filter, and fuel filter. Go up a size in spark plugs helps a lot!

A higher final-drive ratio will give you the cheapest acceleration assuming you won't be doing any freeway pulls.

camshaft, intake and carb and a good set of headers

drop a 350 in it with a 350 turbo trans, new rear end with higher gears

decrease its weight

ROLL IT OFF A CLIFF!