4.0 swap

[WNYBroncoBill]

I have been away from the forum for about five years as I moved to South Dakota from New York State. I shipped the Bronco II here and it is still in very nice condition. My question is regarding a 4.0 swap. I live at 5000' altitude and the 2.9L just doesn't have enough power. I'm interested in the "easiest" swap I can make. I believe that is a 1991 Ranger 4.0 swap. Is this truly a "plug and play" swap with all wiring and components compatible?

Could I purchase a Jasper 4.0L rebuild and simply do the engine swap? Is there another reasonable swap (later Ford 2.7 that could be adapted to utilize the 5-speed manual transmission and existing transfer case and running gear components?

Any help would be greatly appreciated. Vehicle usage is for snow plowing in winter (new SnoWay plow installed and in summer for Forest Service trails and roads in SD and eastern Wyoming.

Thanks,

Bill

 

[ghosttrain2]

I bought a '94 Explorer and installed the 4.0 from it into my '86 Bronco II. At the same time, it also got a 5 speed from a Ranger, and a manual shift transfer case from the boneyard. I used the harness from the Explorer, and spliced it into the Bronco's harness. (Lights, gauges, and so on) Love the way it drives now, and I still have the Explorer to rob the axles from.

 

[410Fortune]

Best thing to ever happen to a bii is a ohv 4.0

Even if you buy a crate engine you will still need a donor vehicle for many many parts, wiring, plumbing, sensors….

Yes a 91 4.0 would be the easiest swap but a 93 is far superior
93 has better wiring harness and power distribution
93 no egr no cam synchro and two 02 sensors


In a perfect world I would use a 98-2000 ohv engine with a 02+ manual trans and 1354m t case. For my own use I would keep the plastic intake and obd2 computer and do a full conversion to the later pcm and intakes.

The 91-94 4.0 into a bii has been done many many times the information is out there

Some Misconceptions are
“You must use the explorer dash to make so easier” not true at all I still have. My 88 dash and I hate the way the later dash fits the bii so I will never give it up

“You can’t use clean fire heads with the early pcm”
Meaning you can’t run a 98+ 4.0 with a 93 computer which is complete bs… I’ve done every possible Combo of this swap and it has never been an issue, we have put thay argument to bed, again, just recently

Do not under any circumstances use the original bronco ii 5 speed behind your new 4.0. The early 5 speeds have crappy gearingand won’t hold up to the new power. (Mitsubishi and Toyo kogo, the Mazda is better but still… find a late model Mazda 5’speed and use it. I also use the larger sohc clutch and drill out the early ohv flywheel to accept it

Food for thought

2.9 is a boat anchor,’good engine for a car,
Never should have been in a bii. Once you have a 4.0’you will see