This is Ms Wrench and I can answer your question about getting more horsepower out of you 1994 Ford F150 302 5.0L. Without spending alot of money, what you can really do is get back some horsepower by upgrading or replacing components that rob horsepower and make the engine work harder.
The first thing you can do is to upgrade your exhaust. Get rid of the stock catalytic converters and install a high flow cat and a nice muffler from the manifolds back. You can get that done at any exhaust shop and it shouldn't run you more than a couple hundred dollars if you go the economy route. You will notice the difference right away, old catlytic converters and mufflers rob performance and horsepower right away and on a truck of that age it probably needs to be done anyway.
Exhuast headers could also be added for a nice performance boost, you could spend a ton of money on them but you can also get a set for a couple hundred bucks or less that will bolt right on. If you are thinking of doing this plan it together with your other exhaust work to save on labor.
These dynomax headers are $221.00 at http://partstrain.com.
Another component that robs horsepower from the engine is the fan clutch. Get rid of that fan attached to your water pump pully and install a Flex-a-Lite Black Magic unit. These fans move air!! You can get the mustang setup which costs about $200. It comes with the fan controller, relay, wiring, mounting hardware, and instructions. Its adjustable so you set the temp you want your motor at and thats where it stays. Fan clutch elimination gives you back about 17hp-20hp and keeps you running cooler no matter what the situation.
An aftermarket cold air intake will give you a boost and would be a good match for the new exhaust. A K&N style filter and performance enhanced cold air intake tube are always an improvement over stock induction and you will feel the extra power.
Depending on how far you want to go the next area to get into would be the ignition. You could add an MSD Blaster or other high output coil to your stock ignition system, or you could install a ignition controller as well. For example, MSD delivers a rapid multispark that burns fuel in the cylinder much more efficiently than the stock ignition and yields performance and gains as well.
Performance chips are also abailabel from JET and other manufacturers. A chip would be best if you do go with the headers and other upgrades to maximize your potential.
Hope this helps, Thanks for using JA