BroncoII4x4.com

So I have a 1988 bII with a 2.9 5-speed and now that my rear main has sprung a leak and the engine's hit 140,000 miles I've decided to pull it and rebuild it, but Ive found a 4.0 L from a 1990 ranger 2 WD Automatic with 12,000 miles on it and the owner said i could have the whole truck for $500, it is just missing the front clip and some of the front frame. I know i need to pull the radiator, computer, starter, fuel lines, and wiring harness from the ranger but will my 5-speed work with the 4.0L, if so do i need a ranger clutch? If not will my transfer case fit up to the rangers automatic or will i need to find a 4WD ranger transfer case? Also if I can keep my 5-speed would I need a computer for a manual 4.0L from a ranger then? I just want to know how many extra parts I need to start looking for. Thanks.

Your tranny will fit, so will your clutch/pressureplate/flywheel- but a Ranger unit is a larger clutch. Use the 4.0 ecm, it will code without the proper tranny hookup but it'll run just fine

actualy its not realy just the ranger, the 4.0L has a lager flywheel/clutch. you can use the 2.9L flywheel/clutch on the 4.0L though. if you use the 2.9L stuff you need to use an auto starter because of the diam. of the flywheel. if you get the flywheel with the motor I would just use that because it is a big advantage over the 2.9L flywheel.

Is there anything else from the exhaust system i need to take besides the headers? Or will i be able to fit the old cat-back system to the new headers close enough to weld it together with an elbow piece?

i did my 4.0 swap from an explorer, and my stock manifolds on the explorer bolted right into the stock y tube from the 89 bronco II with 2.9 liter 4x4 i have, so i dont know about yours for sure, but i would assume it will match up pretty close... depending on motor and year your going to switch from... and make sure when you get the wiring harness to get the EDIS module located on the radiator support behind the battery for the 4.0 becasue you need it to run the coil packs on the 4.0 ignition system.

my ehaust didn't match up, but my 4.0L came from an areostar...worse case you will need to have a new y pipe made.

my 4.0 came from a Ranger, mated perfectly to my stock 88 y pipe

well i did my 4.0 switch from an explorer and i had to get the fuel lines, the throttle linkage, and the radiator, fuel lines from the filter forward high pressure and return line form that point becasue they didnt match exactly, and i used the 4.0 readiator, becasue its a dual flow element and my 2.9 was a single flow element, i used my stock y tube from headers back from the 2.9 and i used my stock manual 5 speed and clutch and flywheel and pressure plate, but you will need to grab the starter from the 4.0 from what everyone tells me and i know on my explorer 4.0 the 2.9 starter would have grounded to the oil pan ..... :D

I think I am going to use a 4.0 L starter, clutch, flywheel, and clutch slave hooked to my 5-speed so I dont think I'll have any issues burning it up. When everyone says the hardest part is the wiring not matching, what part of the harness are they talking about?

i just did an 89 bronco II to 4.0 send me an email address and ill help you with it when you get there..

mine runs fine now, other than the cluch problems i had

but basically its the difference in colors, plugs, and going form distributor to a distributorless ignition.
my email is paulbelden1@sbcglobal.net

make sure you buy a chiltons book for each motor becasue the wiring diagrams are better in it than in the haynes books....... it will help with the process.

although bob has an 88 and he might be the better one to ask about it for that reason, since my wiring is a little different than his.

when you do the swap you have to use the 4.0L starter. the 2.9L starter wil NOT work.

the wiring will be different from swap to swap just cause ford didn't realy stay consistant threw the years. you will just have to break the harness apart and rewire the connectors that run into the firewall.

DBrown wrote:when you do the swap you have to use the 4.0L starter. the 2.9L starter wil NOT work

Even if the 2.9 starter won't work,, I used it any way, with an automatic tranny.

yeah i know the wirinfg wasnt consistent over the years but depending on what he gets his 4.0 from if i have the books to cover it, i would be willing to help him with it.......