Not sure all the years, but the Explorers ran some version or another of the 5.0 for a WHILE, up until 98 or so? Until the redesign....they couldn't fit the 4.6 in the Explorer body so they kept with the 5.0 until they widened the 'sploders, then they dropped it....
I know the explorer shortblocks you buy from Ford have hypereutectic pistons, and Im sure 93+ bottomends are hyper....
'96-'early '97- Gt40 heads and intake has internal EGR (Fox style)
Mid '97-'01 GT40P heads and intake has external EGR ('94-'95 Mustang style)
P heads need P specific shorty's from either FRPP or MAC.
BBK or MAC LT'swill also work with 90* plug boots and a cut down plug socket to chang the plugs.
GT40's require no changes.
If you have the internal EGR intake, you're golden. If not, you will have to delete the EGR or run '94-'95 P headers, EGR, tube, and elbow. That will also mean a '94-'95 CAI or factory intake plumbing. (Most people just delete the EGR)
The exploder cam is designed for a heavy truck with low RPM and towing in mind, so at the very least swap in you're stock H.O. cam. If the engine is low mileage, the valve springs will be o.k. to re-use. The '93-'95 Cobra's typicaly dyno at 230-240 rwhp with a slightly wimpier cam then the stock H.O. You should be good for low 13's. Maybe a high 12 with slicks or DR's.
A very good cam choice would be the TFS stage 1, along with the TFS valve spring kit (You will need this with any cam- the stockers won't take it). That should net you a very high twelve with a 5 speed and good driving. This combo generally get's 260-300 rwhp depending on supporting bolt-on's, engine prep, and tune.
He is right on the money. I actually got a 97 engine that had the p heads, yet still had the good intake with the internal egr ports.
keep in mind, the explorer gt40 or gt40 p heads won't have the internal passages for the smog tube. You can either have those drilled at an engine shop, or delete them like I did. They only fuction to pump air into the heads when the engine is cold, and un necessary when warm, and you don't smog a cold engine.
as well, imo, if you swap the cam out with anything other than that explorer cam, I'd def change those valve springs. My explorer motor revs to 6k, maybe slightly past that, (stock ho mustang cam) and the stock explorer valve springs will likely start floating somewhere in the 5k range.