what are the differences between these 2 engines or are there any?

 

there are no major differences between the 2 blocks and cranks. But after that, there are many differnences. Your explorer has a roller cam, and a lot of goodies like gt-40 (or gt-40p) heads, the cobra intake. Your explorer has the newer generation OBD-V ECU, and a "distributorless" ignition system and Mass air EFI.

Do you have an upgrade in mind for the future?

 

i thought the '94 had a roller cam aswell...wasnt for sure about the heads on the '94 though

 

I'm pretty sure the '94 is a roller and if weren't then the blocks would be different. The difference in a roller cam and a non-roller is in the block in factory form.

 

Ford used a roller ready 302 from about 87-on, so the block would be the same even if it didn't have a factory installed roller cam (although it should). It would just need a couple of holes drilled and tapped for the lifter spider hold-down bolts.

 

+1 on that.. I just pulled the roller assembly(spider, dogbones, pushrods, retainer) from a junkyard motor and swapped the flat tappet cam out of the '90 vintage 5.0 block I have for a nice roller cam. It was a direct bolt-in as the pedistals in the lifter valley were drilled and tapped already.