So I'm new to this And was wondering what solid axel i should install on my 86 Toyota Pickup Truck extend cap. I don't want the tire's to pop out at all want it to look original and I'll be putting a 4bt Cummins engine intoy truck as well with 6 speed Allison automatic transmission.. not going to use it for any crazy rock climbing or anything like that just as a daily driver and every now and then get some mud on the tires any recommendations on what axel i should install?

 

If you want it to look stock, a stock axle is probably your best bet.

The 4BT is huge. It's shorter than a 6BT (since it's pretty much a 6BT with two cylinders removed), but the architecture is the same, it's just as tall and wide. It's going to be a chore putting that into a Toyota minitruck. Also wouldn't be surprised if the Allison was way bigger than the trans tunnel allows.

 

I'm not familiar with the 4BT, but I'll bet you will need some lift from the solid axle swap in order to clear the oil pan and such, so if that is the route you REALLY want to go you should start there.
Cut everything out/off, install your engine/trans/tcase then figure out what axle/lift you want. I don't know what you'll end up with for a T-case to connect to an Allison trans, this may dictate a driver's side differential so plan ahead.
If you have to go really tall to clear the engine you might want more width so it doesn't look dorky and want to tip over.
Using a Toyota axle generally means using spacers to make the width match the rear end width, tires sticking out comes from wheel back spacing and tire size.
If you go with a common engine swap and/or solid axle swap you will find lots of info and help available, if you go down the oddball route you may be breaking new ground.

 

So there's no solid axel i can put into my truck without the tire's sticking out then? Yes going to put a lift so the tranny can fit and going with a diverse transfer case and the truck is completely gutted.. right now i just have the frame with nothing on it because going to get rid of the tention bar's and going with the coilovers then get the frame blasted and painted once i get that installed I'll start peacing everything back together..just don't want the tire's to stick out at all and going with a 5 to 6 inch lift.

 

get a tape measure and check your rear axle width, then check your donor front axle width, if you are using similar Toyota parts to what everyone else is using you need to put spacers on the FRONT to make it match the REAR. If your tires don't stick out on the rear they won't' stick out on the front.
Does "diverse transfer case" translate to "driver's side transfer case"?
Once again, if you are going non-standard you will likely be on your own.

 

They don't stick out from the back at all and they don't have spacer and the transfer case is diverse which i was told that it could be for both left and right side i believe not 100% sure on that but just know they said it can be on the right since that's what the year and make of my truck side it's on.🤷‍♂️

 

I'm wanting to know is that the 85 Toyota 4runn and truck's have straight axle could i use that on my 86 just want the front one replaced to be a solid since the back already is.?

 

I guess you mean reversible.
I also think you need to research more.
None of us can just tell you what to do or use unless there is that one guy that has done exactly the same build as you.
good luck, I'm done.

 

I think he means divorced transfer case, as in the transfer case and transmission are divorced from each other with a short driveshaft between them.

Your engine choice will require a huge lift. You do not want to add any width. You want it to look stock. These don't all work together. If you want to do this, I'm sure it'll be cool but it's most likely uncharted territory so you can't really expect all the answers.

Yes, an 85 and early Toyota front axle is most often the axle of choice for a SAS. The diff is on the passenger side. It is 3 inches narrower than your 86 rear axle (track width changed for the 1986 model year). The usual fix is to add 1.5" wheel spacers on both sides. With stock size wheels and tires the tire will not stick out. If you add 6 inches of lift, it might be kind of tippy.

 

Not wanting to discourage you but, I don't think there is anyway you will fit a 4bt with an allison in a toyota and have it look stock. 22re weighs about 350# while the 4bt scales in at almost 800# (about the same as a big block chevy). That alone will give you suspension and frame issues. A 5 speed (toyota) 95 pounds (ish) vs and an allison 1000 weighs about 350 lbs. You are adding almost 3 times the weight of a drivetrain + who knows how much additional torque to that same frame which will already be stressed from the weight, plus the fittment issues as listed above

 

I'm in the middle of a straight axle swap on an 86 Xtra Cab right now. I'm going 3 link front and 4 link rear suspension. I'm using a 1985 straight axle. The reasons everyone is talking about wheel spacers to make it wider is because the IFS trucks like your 86 are 3" wider. So your stock rear axle is 3" wider than the 85. To compensate for that, the SAS kits come with 1.5" wheel spacers for the front.

Another way to widen it 3" is to do the Tacoma brake swap.(Or Tundra, etc.) To do this you use your 86 IFS hubs and machine the hubs down so you can use a slip on brake rotor. You buy a kit to mount the calipers. (About $100) You then have matching width to the rear, a slip on rotor brake upgrade and no wheel spacers. I did it on mine.

OR......you can get an aftermarket complete axle in the IFS width like from Trail Gear, Diamond or Ruff Stuff. They also sell the housing and you can put your Toyota parts on it. If you really want to do this without going to a stronger axle like Tons, the aftermarket Toyota housing is going to be much stronger than the OEM stamped steel one. Even Land Cruiser axles, Tundra's and such are stronger but also wider. Maybe look into custom 60's like Rock Jock or something?? Not that hard to narrow a 60.

You are definitely going to have to at least plate your frame to strengthen it. You have a LOT of things to consider to do this. That's a LOT of weight, power and physical size to fit in a small package. But where there's a will there's a way. You'll need money too. Good luck with whatever you decide to do.