Hey all i gotta 86 f150 parts truck with a 8.8 rear end with 3:55's so i was wondering if it would bolt up under my 80 f150 with a 9'' the reason i wanna do this is i have 2.75's right now and it is to high of gearing for my liking and the 8.8 rear end assemble is mint out of the 86 so would this swap work? thamks

 

Yes it will bolt up, although a lot of guys will tell you to swap a new pumpkin into the 9 inch. If you're planning on using the springs and all, you want to check the width, as they could be 2 1/2 or 3 inch. You might need to change spring perches. Also, there may be subtle differences in e-brake cables.

 

why go backwards?the 8.8 is a half decent rear end but the 9" is strong.just go to a pick in pull,pull a pumpkin with the gears you want and re/re it.20 min max.a lot easier than re/re a complete rear end.imo

 

Yeah Red...given all other things being equal, I think the 9 inch is the way to go also. But when's he's already got a good 8.8 it's kind of hard to go the other way...

 

i guess but if it was me it would be easier to change the pumpkin than to unbolt the rear off the springs,undo the brakes(hydraulic and parking)out of both vehicles and praying the u-joint are the same and brake lines match up,and buying new u-bolts,and a full days work as apposed to buying a new gasket and 20 min work.it all depends on how much work you want to do.IMO

 

The 8.8 is not a weak rearend. The 9 inch may be stronger, but the 8.8 is up to the task also.

 

as i said earlier it is a stout rear,i have never had any complaints.it survived behind modified 5.0 mustangs.but i was just saying changing the pumpkin is a lot less work.

 

Yes it will work . I had a 83 bronco and replaced it with a 9 inch from a 79 bronco . It will bolt right You will have to remove the sway bar .

 

I too agree that the 9" is definately the better of the two rear ends. I guess if you look at the dollar amount he would have into buying another 3rd member, versus swapping in what he already has... the 8.8 swap would be more cost effective. I would start soaking the u-bolts and shock bolts with some kind of penetrating oil a few days before you plan to do the swap. IIRC most if not all of the brake parts are interchangeable, not sure if the u-joints are the same though. I can definately say the 8.8s are pretty tough, I know I worked the one in my 84 F150 over pretty hard a few times with 33s on it; never broke a thing. I know they're way tougher than an 8.5" GM 10 bolt.

 

Thank for the replys i dont care about the time it will take me but its the money i wanna get a limited slip locker and so for the 8.8 rear end its around $200 and for the 9'' its $400 and would still need to get 3.50 gears for my 9'' so thats abit of a diffrence plus the springs off the 86 are in good shape my 80's springs are sagged to crap so if i could swap that to that would be sweet. I no the 8.8 isn't as tough as the 9'' but im only running 31's and hardly off road it or get into a place were it puts it to the limit so to speak.

 

the 8.8 is as strong as gm's 12 bolt(uses same bearings).one piece of advice,change the brake flex hose while you are doing the change,the old one is 20+ years old and is probably dry and cracked.just cheap insurance.IMO.

 

Ya il change the lines for sure and get new u-bolts ect anybody else got anything in mind i should look at???

 

I also recommend keeping the 9 inch rear, it is tough. There are tons of parts and
upgrades out there for 9 inchers. My 1981 F-100 has a 9 inch which I upgraded to
a 3.70 gear set and a Auburn Pro differential. Performs real well.

 

What is your budget? I know you are looking at ratio swaps and locker swaps, and it sounds like you have your mnid set on the later rear. An 8.8" takes more time to set up, so that is extra money in labor for a shop to do it. Not trying to break you down, just saying that you might come closer to breaking even than you think. One thing I like about the 9" is that wou can keep the extra pumpkin and swap out centers for towing or mileage on long distances.

 

Might want to consider C-clip eliminators also. On an 8.8 if the axle breaks it will come out of the housing and could really mess up your truck. Cheap insurance IMHO