Seems like the Mustang would have more Horsepower than the Explorer but not sure. The miles on a Explorer were likely put on by a Soccer Mom vs. a kid racing Fast and Furious.

I have both, I can bring them up Thursday or Friday with my axle. Would that be alright?

I've got both also if ya need.

I will answer as many as I am pretty sure of.

The explorer engines actually are better suited for a Bronco. They have more torque and, I believe, more horsepower even. I know their heads are better designed and intakes flow as well as a GT40 cobra intake.

The heads to worry about are the heads with the plugs coming straight out the side instead of angled as a stock Bronco is.

All the years you are talking about should be roller engines requiring the steel drive gears on the dist. rather than the stock cast gear on the stock bronco dist.

All the HO motors have the same firing order as a 351w. So pretty much all the motors you are looking at are different than stock bronco.

I am not sure on the crank hole for manual.

The mustang motors with harness and computer are slightly more convienient BUT really only because they have the computer already. On the newer explorer engines you would "retrofit" them for the mustang injection anyway. The 96 explorer lower intake should have the IAT port in the right place already so that would be easiest to convert. If you are going to go with EFI do yourself a favor and buy a new wiring harness. I had a factory mustang harness I was going to modify to work but all the wires were brittle and the connectors were worn. The mustang harness is still 20 plus years old. New ones are somewhat expensive but well worth it for reliability and convienience.

If I were buying a new motor I would pick the Explorer motor over the Mustang motor. But I would build a 351w for it as top choice!

Don't be intimidated by the EFI conversion....It is far easier than people think and well worth it!

Oh and if you go carb be prepared to run an electric fuel pump(if you don't have one already) as the timing covers don't have a place for a manual pump on any of the engines you are looking at.

Should have told me you needed a picker before yesterday. Would have brought it up.

-What years or style heads use different bolt patterns/styles on the exhaust manifolds.
Want to say the GT40P heads are the only OEM heads you will need to worry about when it comes to manifolds/headers.

-What years or years do I need to worry about the different Dist drive gears?
Not a clue.

-Are all Ford cranks drilled for manual input shafts even if they are Autos of will I have to have a machine shop drill the crank for me if its an auto?
If you're talking about the provision in the back of the crank for the pilot bearing, all cranks should have this.

-What years/motor configurations use a different firing order?
The only motors which will have a different firing order (302/5.0 wise) would be the HO motors.

-Anything else I need to worry about of missed?
Only thing I can think of you are missing would be another 49 cubic inches of displacement.

I'm sure Jesus_man and RJLougee can lend some input in to this as well. Jesus_man is running an EFI 351 and RJ installed it.

Like crawler said, the explorer is probably the best choice. A 1" body lift is plenty for clearance if you stay 5.0. While it is easy to re work the mustang harness, I went w. the RJM cause everything is new. ( pretty good investment)

As for the flywheel, a 50 oz w/ 164 teeth is what you need IIRC to match w/ starter

Im also looking for a mustang 5.0 maf backed by the aod to install. I think that is a killer set-up for the bronco. And for ease of tuning find a MAF motor. Speed density is not as friendly.

I would go with the explorer 5.0 especially since you are looking at 96 or 97 model year. And if the ones you are looking at truly have that kind of mileage I would jump pretty high to get one of them.

If they are complete you get the added bonus of serp accessory drive set up too.

With respect to heads...................if I am correct, the "P" heads started in 2008 which doesn't work with all brands of headers.

My 98 has "P' heads (and no distributor) so I called around and Bronco Hut sells a "P" head specific header and Chuck at BC Broncos says he has modified his headers to work with either style of head.

I say rear EFI tank only. It practically pays for itself vs the plumbing, wiring, pumps and accumulator needed to run 2 tanks. Trust me, I've seen me do it. Plus gas fills run into 3 digits with 2 decent sized tanks.

Thats what I was thinking. The 500 for the 23gal efi is about the same has all the plumming and what not on the 2 tanks.

I have a 351 using the BC manifold plate. It clears but I have a cowl induction hood and a 1" body lift.

Hoping there isn't much of a flow problem like Viperwolf said otherwise it might be up for sale soon

I also have a cherry picker you can borrow if the others fall through.

I have a cherry picker you can borrow

my engine is on zach's engine stand and no.........you can't have either

im a bit rusty on the later model 5.0 but would choose by far the explorer block over any other later model, and a early model 302 bottom end would be tits with the larger connecting rod cap bolts (3/8" vs later 5/16") Esp in a heavier vehicle.