Questions about dropping a '95 4.0 OHV engine into a '91 and keeping 4x4

[Justin_]

Hello everybody, i've been lurking ever since I got my first explorer back in June but just now got myself setup with an account.

Back in November I was looking for a new project and ran into a really cheap '95 4 door 4.0 OHV explorer with 4x4 XLT so I scooped it up. I had it sit in my driveway for a while when I decided to try and see what was stopping it from working. Long story short there was oil in the top of the cylinders and the lower intake manifold. This lead me to start rebuilding the engine just as a fun project and a way to learn about cars.

Right now I have the engine pulled and torn down and I am about to start rebuilding it. My friend is rebuilding the transmission as well. This got me thinking about what I am going to do with it when I am done. The '95 I pulled the engine from was in rather rough shape inside and out. Nothing that's not fixable, but it got me looking at other options.

I found a '91 4 door with a bad engine for sale locally for cheap, and that got me thinking. Could I just drop the 95 engine in the 91? In theory im sure this can be done, but i'm trying to figure out how hard this would be in practice. My original thought was to take the newly rebuilt engine and transmission along with the t-case, wiring harness, and ECU from the '95 and just plunk it down in. I would need to repin the firewall connector but that wouldn't be too bad. But then I realised that the first gen '91 has a manual locking hubs and 4x4 shift stick while the second gen '95 has a automatic 4x4 system.

Here is where I start to have some questions. I want to keep the 4x4 system functional, so i'm trying to figure out whether it would be easier to keep the manual 4x4 system from the '91 installed, or swap over the '95s automatic system.

The way I see it it would be easier to just use the 4x4 system from the '91 as it is already installed, but I don't know if this would cause issues with the '95s ECU and the auto high/low system, if it does cause issues would those be easy to ignore like a check engine light?

If I was to switch over the 4x4 system from the '95 (and i'm not against the work if it would function) does anybody know if it would be as simple as dropping in the t-case, front diff, CV axles, and possibly front suspension from the '95 (along with the vacuum solenoids and lines), or would I be looking at a lot of cutting and welding to get this done?

-EDIT- somebody just suggest a third solution. If I was to keep the '91s ECU and wiring harness in the car (apparently this can be done without issue) and just move over the '95s transmission and engine, keeping the t-case down from the '91 I would think that everything would just play together. Is there any issues that could be pointed out with this? It seems like the easiest solution as I also would not need to repin the firewall connector.

Thanks everyone!

 

[410Fortune]

keep the manual shift 4x4

The 95 ECU wont care as its not the ECU that controls the 4x4 it is the GEM module.
the 4x4 lights in the dash might flash after you convert the 95 to a manual transfer case. No big deal, you can actually cut the 4high and 4 low wires at the gem module and hook them directly up to your new t case....so no more flashing lights = the lights in the dash will work with the new manual shift t case

You do not need to re wire the 95 to the 91 stuff, there is not much difference actually aside from the plastic upper intake, they are both OBD1

This should get you started.