Custom rear axle width recommendation.
 

I'm converting my 68 SWB narrow 12 bolt rear to the CPP big brake package and 5X5 lugs along with a 4.5/6 static drop.

I also plan on buying some BOSS 338's 20X8.5 F, 20X10 R wheels in the near future. Ive also read through the 338 thread....

http://67-72chevytrucks.com/vboard/s...d.php?t=352320

Seams like the rear offset on the 20X10's is 5.5 BS and most guys with the narrow rears are running spacers.

Mark Williams Enterprises ( MWE) is right down for the road from me so I don't have to deal with shipping issues/cost. I think I'm going to have them install the weld-on housing end kits, dump the C-clips, and cut some axles for me. Then I can drop in my eaton posi/3:73's!

I have the option of having MWE widen the rear end assembly while they are at it. It seams cheaper to do this while I'm at it that a custom set of wheels.

any suggestions on over-all width?

Re: Custom rear axle width recommendation.
 

Billet specialties will build you wheels with any backspacing you want and then you wouldn't have to modify the rear end.

Re: Custom rear axle width recommendation.
 

I knew that was an option too but $850 for a set of Boss 338 wheels or $2K for a set of custom set of wheels. For the difference, I can have a solid 12 bolt rear end build that eliminates the c-clips, rolls on a better bearing design, has no "end play" and allows me to mount ANY brake I want onto it while not having to rely on a big back space wheel w/ spacers.

I may go slightly wider than the 71' up 57" width.

Re: Custom rear axle width recommendation.
 

Buy wheels and tires. Pull axle from truck. Put wheels underneath truck and move them to where you want them to sit. Measure between wheels. Have axle made that width. Done.

Re: Custom rear axle width recommendation.
 

Increasing axle length will do you no good with out increasing the housing length. I already checked if they could make the ends thicker, but they are pre forged at a certain thickness. These aren't driveshafts.

Re: Custom rear axle width recommendation.
 

For some reason, I misread what you were trying to do. Been reading too many big tire/narrowed rear end threads!

I bought a Craigslist rear for my truck from a '72 Chevy. My truck is leaf spring so it was harder to find than a coil spring rear. The advantage of this for me is it came with all the brake parts as well. I swapped my posi into the new housing and just double checked backlash.

From a dollars & sense standpoint, a used rear is the way to go.

Depending on the housing ends that they have, they might be able to widen your axle. But you are going to have a ton of money in what is really a stock later model axle.

Re: Custom rear axle width recommendation.
 

Since Mark Williams is right down the street, go see them. They can lengthen or shorten the diff tubes, put the large bearing ends on for you and get the flanges set up for the brakes you want to use, and you get axles measured and machined by them so there's no chance for a measuring mistake!

Re: Custom rear axle width recommendation.
 

That's exactly what I did. For $1200 parts/labor it will be completely set up. Since my stock rear end is 55.5" and the later units are 57", I figured 57" was spot on. But w/o the wheels/tires, I was deferring to someone with experience here who could chime in if I'm out of line ( given the wheel choice).

Re: Custom rear axle width recommendation.
 

Good point! maybe a later model 12 bolt housing would be perfect, but I'd still have c clips on a 500 hp canyon carver C10. Maybe not so much.

Re: Custom rear axle width recommendation.
 

Broken axles don't occur on the street much. Tire spin usually occurs long before any real stress on the axle. Avoid wheel hop at all costs though. Axles break on drag strip launches with sticky tires and clutch dumps and with the leverage from large tires and epic gearing offroad.

Disc brakes should effective retain the axle in case of breakage as well. I am practical, safety conscious, but cheap.

But I don't beat on my stuff NASCAR style either. If you really need the positive retention of the Ford style ends, go for it. But I'd move away from the truck 12 bolt as well, it is a weak link itself.

Re: Custom rear axle width recommendation.
 

I have a history of pushing things a bit. NOT that I think a c clip rear end will be my demise, but I guess its good insurance.

Re: Custom rear axle width recommendation.
 

Like the pic! OBTW, a C-clip rear is a formula for disaster on a truck that will be driven hard in the twisties. Sooner, not later the pin in the carrier will break and one of your tires will try passing you in a turn. At that moment, life gets real interesting!

Re: Custom rear axle width recommendation.
 

Sounds very easy. Where do you get the housing and the axles cut to length? Or order from a place that does it?