4.0 into an 84 Bronco II with a manual trans

[Crippled Eagle]

Hello All
First post here.
I have a very cherry 1984 Bronco II I just bought from the original owner. It has the 2.8 V6 and a 4 speed manual transmission. One of the heads is cracked and will need replaced. While reading over the forums, I find some have put a 4.0 V6 in the 2.8s place. I have a 1991 Mazda Navaho with the 4.0 in it with a trashed automatic. What I am wondering is there a manual flywheel that will work with the 4.0 into my 84 or am I doomed to use the automatic?
I mechaniced for a14 years before going to work for the government, so I have a background for being able to do what is needed to put the later engine in the 84.
I'd really rather use the 4 speed if at all possible as I don't want to fabricate any more than required.
Any one know the answer?
Thanks
Marvin

 

[B2 Addict]

I don't know the answer, but welcome to TRS!!!

Good luck with your project!!

 

[Ozwynn]

you cannot use the 4 spd ...... technically it will fit but it won't stand up. better off finding an M5ODr1 from a 4.0L ranger or an explorer/navajo. but yeah, all the parts you need exist in a junk yard or in a donor, or off the shelf at autozone ( minus trans ....... craig's list, JY, oe donor for that).

 

[Beanmachine7000]

Technically, you could use it, as it would bolt up to the 4.0, but it will not last very long... I would recommend an M50D-R1 also...

 

[alaskan155]

its will bolt up, but its basically this

a ticking time bomb, ready to blow at any minute, unless you baby it(which we know you wont lol)

 

[BlackBII]

Yeah, you could use the 4 speed but.....Boom!

Like previously mentioned, find a M5OD out of a Ranger/Explorer/Navajo

The motor will bolt in, but you will need to swap out all the wiring, fuel lines, computer, radiator etc. It has been done on the first gens, but it's a good amount of work.

 

[Crippled Eagle]

Thanks for the welcome and the info!

Thanks to all that replied!
OK, I have found a M5OD out of a Ranger. Now, I need guidance as to whether it must come out of a 4X4 or are the 2 wheel trans the same. It has a V6. I haven't seen the truck yet. or a visual might answer my questions.
I'm still considering putting the 4.0 V6 from my Navajo in it with the auto trans after a rebuild. The thing is, I am getting older and making mods just isn't my idea of fun anymore. I think I did enough of them back in the 60s, 70s and 80s! It used to be fun staying up all night and going to work the next day, but now.....
Another quick question, has anyone used the Mustang 3 exhaust port heads for the 2.8 in a Ranger/Bronco II? I've got a set of Mustang heads located and the price is really right. I might do the 2.8 head change if they will work until I have enough time to have the Mazda's OD auto rebuilt.

 

[Beanmachine7000]

If your truck is 4x4 you HAVE to get the 4x4 transmission so the t-case will bolt up...