• Welcome to ClassicBroncos! - You are currently viewing the forums as a GUEST. To take advantage of all the site features, please take a moment to register. It's fast, simple and absolutely free. So please join our community today!
    If you have problems registering or can't log into your account, please contact Admin.

81 f100 truck ??

doublehfarm

Contributor
Newbie
Joined
Jan 2, 2021
Messages
28
I just got a 1981 f100 donor truck for free. Hoping to use the 302 for my engine swap. It has auto trans and hoping to use it as well. Any other donor parts I need to save before scrap? thanks
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
42,737
The engine is a direct bolt-in for your original V8. If you had an inline-6 on the other hand, obviously you need to change the mounts/towers first.
Not sure which auto an '81 would have. Were they already AOD's or was it still a 3-speed auto? If so then maybe it's still a C4?
If it's a C6 on the other hand, commonly used in the full size trucks, it's harder to fit under an EB. It can be done, but it's a bigger trans and you find it a pretty tight fit that needs some tweaking.
It's a 2wd or 4wd truck? In a 4wd the transfer case is too wide even in '81 I believe. If it was a heavy-duty truck I think they were still using the NP205 t-case, which is highly desirable to some. If it's the super-long aluminum case (Borg Warner maybe?) then it's too big to fit easily into the Bronco.

The carburetor would be a 2bbl and would work very well. Lots of smog stuff you might not need, depending on what year your Bronco is and where you live. But it actually can get some few bucks for those looking to bring back into specification or doing a religious restoration.

I'm sure there's more. Maybe someone will come up with something cool from your truck.
Good luck

Paul
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
33,085
That is a really lame 302. Hope you plan on a rebuild before using the engine. That engine is probably as weak as they were ever made. Something like 125HP when new.
The AOD did exist, not sure if the truck got it. I think it took a few more years until the truck got that transmission. Now the bad news, that vintage AOD is junk. There were fundimental flaws in the oiling system that starved the planetary gears of oil. Even if it is working, it is likely highly damaged inside. AOD has linkage to the carb only, no vacuum modulator. Vacuum modulator is a 3-speed.

More than likely it will have a 3-speed automatic. C4 would be good, but will still need a rebuild to put a 4WD tailshaft in so it can have 4WD. C6 is more likely and if 4WD what I would expect to find. If the bellhousing is removable it is a C4, if not it is a C6.

Being a free truck, you have to decide what parts are good enough to use again.
 
OP
OP
D

doublehfarm

Contributor
Newbie
Joined
Jan 2, 2021
Messages
28
That is a really lame 302. Hope you plan on a rebuild before using the engine. That engine is probably as weak as they were ever made. Something like 125HP when new.
The AOD did exist, not sure if the truck got it. I think it took a few more years until the truck got that transmission. Now the bad news, that vintage AOD is junk. There were fundimental flaws in the oiling system that starved the planetary gears of oil. Even if it is working, it is likely highly damaged inside. AOD has linkage to the carb only, no vacuum modulator. Vacuum modulator is a 3-speed.

More than likely it will have a 3-speed automatic. C4 would be good, but will still need a rebuild to put a 4WD tailshaft in so it can have 4WD. C6 is more likely and if 4WD what I would expect to find. If the bellhousing is removable it is a C4, if not it is a C6.

Being a free truck, you have to decide what parts are good enough to use again.
yes i plan to rebuild it . anything will be an upgrade from my 66 170. mostly excited for more trans options from the sbf

thanks
 
Top