Hey all, I’ve been looking for info for a while on upgrading the rear end on my f-body (on a budget) and came to the conclusion that most people use explorer 8.8’s because supposedly they all have lsd, and that they have 31-spline axles and disc brakes. I can confirm they all have discs and 31-splines, but they are NOT all lsd. Mine isn’t....

The explorer 8.8 measures about 59” and the 10-bolt about 64.5” so there is a good difference in width hence most people get it widened. But.... I had an 85’ f150 8.8 kicking around and decided to take the backing plates off and measure it ... about 64.5” exactly the same as the 10-bolt, and has 31 spline axles and lsd. The pumpkin looks to be about in the same position as the one on the 10-bolt so I don’t think driveshaft angle would be a problem, Only thing is it has drum brakes. So I took the brake brackets (or wtv they are called) off the explorer 8.8 and they fit bolt on onto the f150 8.8.

my question is why dont people use these diffs? Is there something I’m not understanding here?


visually they look like they are exactly the same width (I measured and they are):



Disc brake brackets on f150 diff:

Inside the explorer 8.8:

 

I'm interested in this....do you happen to know if the axels are the same length?

 

You're going leaf spring?

Nice upgrade. Supposed to be equivalent to a Chevy 12bolt. Surprised more people haven't tried this.

 

OP, you can always cut the axle tubes off of both rears, slide the tubes from the 10 bolt into the 8.8 tubes (requires a sleeve to be machined to adapt them), and use the factory brakes/shock mounts. There are companies that manufacture torque arm mounts for the 8.8 as well to weld in. You can also get a Trac-lok diff from a junkyard out of another Explorer and use Cobra clutches.

 

I like the F150 rear because it has 3 1/4" axle tubes

 

yeah I wanted to keep it as cheap as possible so I will be keeping the axle as is, as for the torque arm I got the hiltsy kit that I will weld on.

 

no sir will be welding on all brackets from 10 bolt.

 

Do you mean if the f150 axle shafts are both the same length?

 

Sorry I should have been clearer. The explorer rear ends have the offset pinion - i think driver side is longer than passenger or something. Is the f150 rear end the same length on each side, pinion in the center?

 

When an 8.8 is used, it's because there a guy/shop in Texas that uses the 8.8 center section and your stock 10 bolt tubes and fabs them. I can't post his info due to "site rules". I don't wanna go to "LS1tech jail". LOL
But his stuff is holding serious power.

but here's an old post as well
https://ls1tech.com/forums/gears-axl...8-8-build.html

 

sorry for the lack of precision looks to be between 2-3 inch difference not more.

 

Keep us updated (fellow Canadian!)

I'm really curious how this pans out. Ive been wanting a new rear end for the car but dont have the fab skills to do a full cut and weld rebuild, so something a little less involved would be awesome.

 

Sounds good buddy!

 

Any update on this? been scouring nearby junkyards to try and find an 8.8

 

So i've been waiting on several things to finish up the electrical in my workshop so that i can weld the hiltsy mount and brackets, but so far looking good. Think im going the custom axle route, getting strange 8.8 axles with a 10-bolt bolt pattern, and then seeing whether the caliper setup from the explorer clears the wheels. If not going to try and adapt brakes from 10-bolt onto the 8.8. Either way this is very doable, the biggest thing for me was the width and getting that correct. Since i won't have to touch that part, simply cutting the brackets off the 10-bolt and welding them on the 8.8 will not be a huge undertaking at all. Measure twice, weld once .

 

Update:

I cut the brackets off my 10-bolt with a plasma cutter, but decided to change routes after doing this because prepping the brackets from the 10-bolt to go onto my 8.8 would have been too time consuming. I decided to buy brackets from racecraft instead. They are heavy-duty 3/16 steel, and are made to already have lower holes to relocate the control arms much lower, replacing the need to add relocation brackets. They are made for 3-1/4 inch tubes, which is the right size for the f150 8.8 (explorer has smaller tubes, 2.8 inch i believe).

Here's the link for the brackets i will be using: https://www.racecraft.com/housing-br...kit-p-706.html

I got my TIG welder setup, and after spending a couple hours at the welding shop talking to some experienced welders, made my first attempt at welding what i beleive to be cast iron (center housing) to steel tubes, it turned out alright. Used lots of preheat, left the torch heating while i made several little passes all around as to not warp anything, then i made a bigger pass over the little one. The result looks ot be pretty solid.




I will be starting the Hiltsy mount tonight, will post updates.

 

Nice! looks good!

Are you keeping the stock diff in there? I think thats where I'm having my biggest issue on building an 8.8 - Car should be in the 800-1000 range, and was going to slap an S-trac in there..but then that ruins the budget side of it and makes it nearly as much as a 9inch.

Also with the axels - every place I look seems to show that you need to change out the housing ends when buying axels? What am i doing wrong in my searches?

 

Cool man that is also the hp im going for when my build is done. Im also building a T56 at this moment, with an SSR 32-spline mainshaft (supposed to be good for around 1000hp) and all the other typical upgrades.

As for the diff, at this point, i think the most budget friendly and solid option would be a spool. I've been researching this option and many people seem to not mind it on the street at all. As for the axles that seems weird as you can get your axles custom made, and most aftermarket axles on summit say ``direct fit`` but im not sure. Could always reuse the stocks till they break or maybe get the stocks cryo-treated? This is supposed to solidify metal quite a bit, i got it done to some of my trans parts.

More to follow on the hiltsy kit as my kit is missing a part, which hiltsy will send me ASAP. His customer service is excellent!!

Check this beefy biatch out, 32-spline cryo-treated mainshaft should be good for 1100ish hp.

 

So seems like these could possibly do, they don't mention anything about having 9`` ends, they say direct fit. Also from their info, one axle is exactly 2 inches longer than the other. Mine is from an 85 f150, not sure this applies to all years.

https://www.summitracing.com/search/...spline%20axles

And another reason it'd still be better to use an 8.8 over a 9 inch is weight, and how much power it robs to turn it, so...

Plus shipping and duties would cost a fortune for me, is another reason im not ordering an assembled rearend.

 

*update*

Sorry it's been a while, pretty busy on other stuff. I mocked up the Hiltsy mount last night, seems to fit very well. The only parts that don't fit as well on an f150 8.8 are the two little tabs that go over and under the driver side rib, and the vertical tab on the driver's side as well. I had to grind the two little tabs to get them tucked in a little more, and the vertical tab does not have the holes in the right spot for the f150, but i will be welding it instead of bolting so i don't really care. Overall hardly any modification to get it to fit!