For the original question of this thread:
Consider this... You are currently in school in Buffalo. You graduate and get a nice job offer, say on Long Island near home, or DC area, or god forbid CA.
If you can't pass inspection you just acquired an "off road" vehicle that you can't drive on the streets.
As for the 96+ Explorer engines:
These are 5.0 engines. If you have an early X, like myself, you can use a 96+ explorer engine and wire it up using a 89 - 93 Mustang, T-Bird, or FMS Hot Rod harness and EEC IV computer.
There are some simple modifications that must be made, but nothing serious. There are no electronics problems / incompatability... It works
- Drill & Tap ACT sensor port into the lower intake manifold.
- Change some of the wire harness connectors (I only had to change the TPS connector and the A/C compressor connector).
- Build an intermidate harness to connect the FMS main harness to the 4.0 Explorer harness.
Use of the air pump might be considered optional, I did not install the air pump (there was non to install).
My 92 Explorer XLT with:
96 5.0, ported GT40 heads & Explorer intake,
65mm Explorer TB , C&L 76mm MAF,
FMS wire harness and sensor kit,
A9L EEC IV (used 89 mustang manual trans),
headers, new CAT, 3" exhaust
Passed Colorado emissions inspection (Fed. standards)with flying colors. The emmision values were so low I almost didn't believe it. The emissions test does not perform a cold start test which is the purpose of the air pump system. Technically it is unclear if the air pump would be required or not. I talked at length with an emisions engineer at the state (He was very helpful). His opinion was that at a minimum I had to pass the 92 standard, which did not require an air pump on the 4.0, but all other ford vehicles with the 5.0 had the air pump. He recomended installing the air pump, but admitted that the vehicle would probable pass the inspection without it.
Your vehicle model year sets the base line for the emmisions standard. If you use an earlier engine than the model year you will have to add the pollution control system for the model year. To put a 5.0 in a 96 or later Explorer will require that you maintain the OBDII computer. I would recomend an Explorer engine in this case, not a pre 96 5.0. You will need the Explorer 5.0 wire harness and computer, but it should not be too difficult to wire.