Hey wasn't meaning to cut down your 4.0L. Heck the power jump from the 2.3L is probably what Shelby got with the first Cobras. The question was if Shelby would have liked the idea. Yes I think he would have, but I also think he would have wanted a bigger motor. I honestly think he would have installed a 302 or 351, though the supercharger on the 4.0 as you mentioned could have happened as well. Hey it's your truck, you build it the way you want. If you get tired of it I'm sure you can do just as good of a job on what ever motor you decide to put in it's place.
Not to mention I did what I could afford... I have less than 4 grand in the whole build... I'd be willing to bet with a 3.73 in it It would have a ton of tourque... Personally I like the fuel milage so it is what it is.... One day I'll probably put a 5.0 only when I find a complete Explorer with one that I can buy and enough cash to build the engine from the ground up....
I understand that. If I could have afforded it I wouldn't have started with a complete Explorer though. I eventually want to swap to manual and the 5.0 explorer didn't come with one. I would have used a stroked Explorer engine mated to Mustang EFI and a TKO transmission. The Explorer EFI setup is doable (I'm in the middle of it) but the Mustang EFI is a lot easier to install. As for my build, at the rate I am going I think I'll be at $4000 before the truck is even driveable. I'm almost at $2000 already, that's the 86 project truck, the 99 explorer donor, the Mach wheels w/tires, and the big brake kit (still need the brake components). Shouldn't have much left to buy but what is left will cost, definitely won't have it driving and painted for $4000.
To even add more to how well the 4.0 performs.. Mine has over 100,000 miles on it and still I'd drive it anywhere...
My 4.0 (in the 99) has 175K on it and I'd still drive it to... the junkyard. That's mine though and since I didn't get it until 90K, with a lot of hidden problems, who knows what happened to it before it became mine. At this point it's a dog and seems about wore out, so that may be biasing my opinion to the negative. If I replace the motor in this thing I doubt it would be another 4.0L, I'll probably find another totaled Explorer V8 with AWD to swap in. I have a feeling the 4.0 is going to get replaced with a 390 FE, unfortunately for the Ranger I don't feel like making it fit.