OK, I assume we're only talking about the 73-87 (91 for 1 tons) SFAs here. The 3/4 tons always have a D44 in the front, generally a 8 lug one. THis is the same axle as the 1/2 ton just with bigger brakes and 8 lugs. 3/4 ton rears can be either a 14bff or a sf. 1 tons were available in dual and single rear wheel, always have the 14b ff and a D60 front axle (after 77 I beleive, 44s before that). When you talk about the big offset I assume you mean on the duallys, I beleive that's so one spare tire fits in any location on the truck.

 

Ah... one spare tire to fit all 4 corners... didn't think of that.

I wasn't sure whether the 14FF differed between 3/4 and full 1 ton trucks - I've seen some 1t duallys with the outside rear wheel removed and the axle looks different than the 14FF under my truck (hub looks longer)- must be an optical delusion brought on by the offset of the wheel.

Pre `77 1t's had D44 fronts??? It's gotta be pretty difficult telling an 8 lug D44 from a D60 front.

 

I think the drum is a little different between the duallys and the single wheels, so you probably are noticing that. I've also heard some scuttlebutt that teh dually axle is a bit narrower - 62" as opposed to, er, something a bit wider...

Yeah, the early ones had 44s from what I understand. The easiest ways to tell the difference if you can't tell immeadiately from the size difference is one of 3 ways -
[*]D44s have ball joints, D 60s have kingpins
[*]The passeger side spring is held on by 2 ubolts on the 44, but on the 60 the inner side uses two bolts
[*]On the 44s the steering arm is that half circles looking deal, while on the 60 it's just a straight arm that bolts to the to of the kingpin.

 

Let's see what I can add in here. I just put a 14ff single wheel in my 87. I also have a 14ff dually in another truck. The dually rear has it's spring pads in about an inch on each side. The shock mounts are moved in (top of the shock mounts to inside of frame). The drums are twice as deep, and set in more on the hub. There is about a 1/2 inch between the drum and the spring. The hub does stick out further, by 3-4". The axles themselves and the diffs are the same though. Not much else is. You can't swap one for the other, and the dually, budd, wheels won't fit on a non dually rear. It's pretty easy to tell a 44 front from a 60. It's stamped 44 or 60 on the webs between the pumpkin and the tubes. 60 should have king pins instead of ball joints. 60 also has 4 bolts to hold the steering arm on, where the 44 has 3.

 

14FF's big difference between 3/4 and 1 tons are the size of the brakes and the location of the shock mounts and spring pads. In closer on a 1 ton, and the brakes are bigger on the 1 ton axles.

The 14FF was only under duallies for a couple of years, and GM has put the D70 in the rear of duallies since the mid 70's or so. I too have heard that Dually rears are narrower too. Was thinking about using a Dually for a trail truck, just running single rear tires, but the D70 thing and the narrower than normal rear axle kinda put the kybosh on that plan.

 

I always though a dually would be sweet looking with BIG FAT single BOGGERS on the back end, and normal width ones up front.

 

I was thinking just run Bushwacker cut outs up front so the wider track front tires were somewhat covered, and maybe swap in a 14FF out of a single rear wheel truck for the rear.
Maybe some 1-1.5" spacers for the rear to get the tire tracks closer together?

The Detroit for the 14FF is $350. The Detroit for the D70 is $550.

I can get a working 14FF for less than $200.

I can have the 14FF's spider gears welded a la Lincoln Locker for $40 or so. Free if I learn how to weld.

Hmmmmm....................

 

If im not mistaken the cab&chassis 14 is narrower than the dually pick-up 14!

 

The axle is not narrower the perches are.

 

Not sure who said it but all the duallys I have ever seen from GM have had 14bolt FF's in them. My 97 1ton crew cab dually with a 6.5L has one with 4:10's.

Ryan

 

The spring perches are 1.25" (on both sides) closer in. I know because I just did it to a 1T 14bolt I got from RyanB. Hi Ryan!

 

How is the project going? havn't seen you post for a while on here! how are the axles? hopefully great! I just finally am now getting to fab up the brackets for those coil-over shocks I got from you.

Ryan

 

I think I read some were that 'burban rears are narrower than truck ones. Any one else hear this because im geting a 3/4 ton 14ff from a 'burb also a set from another 'burb of a 12bolt and a I believe a dana 44 front. Also an NP203 with adapter for th350 so Im half way to a doulber.

 

The Burb axles are the same as the ones from a 3/4 ton truck.