I have a 93 flareside with a 5.0 in it. What are some bolt on power adders I can do on the truck that won't break the bank. And how easy would it be installing some gt40 heads from an explorer on it and how much power would I gain? There's tons of the 5.0 explorers where I live at the junkyard

 

Won't break the bank is very subjective. I think you're on the right track with the heads though. Something to consider though about those is there are two types of GT40 heads. Most of the Explorers that you have near you probably have the GT40p heads. They will work, a lot of people like them because they are a great factory bolt on and go head. The regular GT40 heads have bigger combustion chambers than the p's but the p's may cause you trouble with the exhaust manifold/header.

Ford Racing makes a header that works for the Mustang with the p's but it may not fit yours very well. I don't know about that.

Either one will work, but they both have their pros and cons. The bigger combustion chambers on the regular GT40's won't give you any compression upgrade either.

With all of that said, any of the heads you pull from a junkyard may need going through to see if they are usable/straight/not cracked. None of them will come with good springs. They will more than likely be worn out. Also, depending on what cam you have, and I think in '93 they were running a flat tappet, the springs will have to be matched to the cam.

I don't know how deep you plan to get into the motor but if you're considering a cam, it would a good time to upgrade to a roller cam from the flat tappet (if it came with a flat tappet).

Incorporating some Mustang stuff into the build can help too. Like Mass Air conversion, intakes, throttle bodies, etc.

So lots of options.