14 Bolt SF 6-lug Conversion

I know most of you guys prefer the 14bFF, but I decided the SF was a better choice for my needs. I picked up an 8-lug 9.5 14 bolt for $175.00 about a year ago and converted it to 6-lug, regeared to 4.10 and added a locker. Here are a few pics of the project. WMS to WMS measures out to 67.75in, which is about the same width as the front. I'll take some pictures of it installed in the truck and add them when I get a chance.

14 bolt 9.5 carrier compared to 10 bolt 8.5 carrier​

1-in spacers made from .75x.12 DOM. Faced on lathe This is meant as only a temporary solution; I'm thinking of converting to disk

I shimmed the wheel bearings out 0.1in by using a 0.020 in shim to get bearing surface of the axle shaft to fully ride on the bearings. You can see the shim if you look closely behind the bearing. I ground the ID of the shim at the bottom of tube to insure plenty of oil gets to the bearings however; the oil level is higher than the shim ID anyway.

Axle shaft installed with 1/2-20 Ford lugs pressed in to replace the 14mm GM studs. These studs work much better with the stock Chevy rims. I bought one new axle shaft from 4WParts because it was the same price as the local junk yards were charging for used; about $110.00. The other shaft I got used on ebay.

Powertrax No-slip installed. Someday it will get a Detroit, but I picked up this locker on Ebay for a good price.

I forgot a few details:I shaved about .2in off the bottom of the diff. leaving me with a minimum ground clearance of 9in with 33in tires @ 35psi. That's a loss of about 0.75 in from the 10 bolt. (I measured before and after the swap on flat, level pavement.)

I also swapped the 1350 yoke to the 10 bolt Saginaw 3R yoke so I didn't need a conversion joint.

I'm going to link this thread in the "14SF tech" thread I started awhile back if you don't mind.

Click to expand...

Linking the threads sounds like a good idea. That first thread is what motivated me to do this anyway...I should have just added to that thread instead

The studs are for 68-96 Ford 4x4 F150 front wheel studs. Doorman part# 610-219. The knurl diameter is 0.625in and the overall length is 2in. I think the knurl diameter for the factory 14mm studs is 0.620, so they are a very snug fit. If anyone is planing on using these studs make sure you press them in or pound them in from behind. The fit is too tight to pull them in with the lug nuts.

Yeah, black widow perfomance sells disk kits, but I made my own. I can get you some measurements if you want, but I used good ole caddy calipers and rotors off the front of a 89-98 4x4 1500. I mounted them on the outside and my axle width is perfect.

I am using 9/16 studs that I took out of the 8-lug axleshafts. I built the disc brakes out of a bunch of stock parts. The backing plates are the same as stock front ones, but opened up for the large tube - the "temporary" spacers have been there like 7 years now? The hoses, slide pins and calipers are all stock front parts. The rotors are mid 90's front 4x4 rotors which fit perfectly on the 6-lug shafts. I do have to trim a bit of the brake pad metal whenever I replace them (which is rare). I run an adjustable prop valve to lower pressure to the rear brakes. Really, front calipers are too big and just lead to increased pedal travel. I'm sure I posted more details somewhere....

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