zakk
1/2 ton status
The 14B swap is any easy and bulletproof upgrade to any vehicle. The greatness that is the 14 Bolt Full-Floater (Forthwith known as 14BFF) axle is we documented. It is so strong, and so cheap to purchase, rebuild, and upgrade that there are more than a few Ford's and Jeep's that run this monstrosity of an axle.
To convert your 1/2 vehicle to 3/4 or 1 ton, you will need to find a 14BFF. Prices will vary from $0 - $300 for the unit, depending on your part of the world you call home. Most agree that $100-200 for a good unit is reasonable.
Where do you find such an item? A junkyard, your neighbor's rig in his driveway (they are that common), or Salvage shops. There are many to choose from but we will assume you will be looking for a pre-AAM 14BFF (70's-80's) for this article.
Variations of the 14BFF:
K30,C30: narrower spring perches that will have to be rewelded, 2WD versions will also need new shock mounts. *Pre 1973 vehicles: This is a direct swap in, with the above mentioned notes (Beast3888)
K20,C20: The K20 is a bolt in for post 1973 Rigs. Get the 8 lug conversion pieces for the front while you are at it. C20 will only need the shock tabs reworked
Van 14BFF: The most desirable version. Specs differ depending on the year, but they are wider than a truck 14BFF so your track width will be the same (or closer to it)
Gear ratios are between 3.73 and 4.56, with 4.10 being the most popular by far. A Deee-troit locker is the only available locker for the unit, and is substantially cheaper than any other locker out there. In addition, the strength of the 14BFF and the Deee-troit = bomb proof, IMHO. I don't carry spare anything for my 14BFF (which is equipped with a Deee-troit, also) save a driveline u-joint.
Swapping the Unit it:
If you were lucky enough to get a K20 14BFF: remove rear drive line, disconnect e-brake, remove axle, install new axle
If you got any other 14BFF, you will most likely need to reweld the spring perches. IMHO, this should be done by a well trained welder. A professional if you can find one. Now is also the time to look at making any pinion angle adjustments.
To remount the shocks, use your imagination. What I did won't work for 95% of you, so I won't even bother. As your having your spring pads rewelded, talk to your welder about some simple mounting tabs.
To utilize your existing (stock) driveline, a conversion driveline u-joint must be used. Napa #348 u-joint is needed if you are replacing a 12 bolt, a Napa #447 is needed if you are replacing a 10 bolt.(Bowtiered & Beast388). A good driveline shop will be able to help you on this, or call Steve at South Bay Drive Line (408-995-6000) who seems to have every U-joint memorized and is cheaper than most mail order outfits. Tell him Phat zakk sent you. He'll then know your working on a Blazer of some sort.
E-brakes are on a case by case basis. Mine work, but they aren't as tight as they used to be. Adjusting them is a fo-sho!
Other issues to consider:
The 14BFF is also affectionately known as the land anchor. while doing your swap it is a good idea to lop off 1" of the lower lip. this leaves well over .3" which is plenty of metal. Some have gone as far to make the 14BFF a 13BFF and turn down the ring gear and then plate the bottom. Remember: Ground Clearance: every 1/4" counts!.
Also, the 14BFF is an 8 lug axle. It can be converted by use of adapters (one company is Echobit.com) to make it 6 lug, or you can swap 3/4 outers from a K20. You deiced what is best for you.
And with that, I'm going to treat myself to a frosty Diet Coke. Good luck.
To convert your 1/2 vehicle to 3/4 or 1 ton, you will need to find a 14BFF. Prices will vary from $0 - $300 for the unit, depending on your part of the world you call home. Most agree that $100-200 for a good unit is reasonable.
Where do you find such an item? A junkyard, your neighbor's rig in his driveway (they are that common), or Salvage shops. There are many to choose from but we will assume you will be looking for a pre-AAM 14BFF (70's-80's) for this article.
Variations of the 14BFF:
K30,C30: narrower spring perches that will have to be rewelded, 2WD versions will also need new shock mounts. *Pre 1973 vehicles: This is a direct swap in, with the above mentioned notes (Beast3888)
K20,C20: The K20 is a bolt in for post 1973 Rigs. Get the 8 lug conversion pieces for the front while you are at it. C20 will only need the shock tabs reworked
Van 14BFF: The most desirable version. Specs differ depending on the year, but they are wider than a truck 14BFF so your track width will be the same (or closer to it)
Gear ratios are between 3.73 and 4.56, with 4.10 being the most popular by far. A Deee-troit locker is the only available locker for the unit, and is substantially cheaper than any other locker out there. In addition, the strength of the 14BFF and the Deee-troit = bomb proof, IMHO. I don't carry spare anything for my 14BFF (which is equipped with a Deee-troit, also) save a driveline u-joint.
Swapping the Unit it:
If you were lucky enough to get a K20 14BFF: remove rear drive line, disconnect e-brake, remove axle, install new axle
If you got any other 14BFF, you will most likely need to reweld the spring perches. IMHO, this should be done by a well trained welder. A professional if you can find one. Now is also the time to look at making any pinion angle adjustments.
To remount the shocks, use your imagination. What I did won't work for 95% of you, so I won't even bother. As your having your spring pads rewelded, talk to your welder about some simple mounting tabs.
To utilize your existing (stock) driveline, a conversion driveline u-joint must be used. Napa #348 u-joint is needed if you are replacing a 12 bolt, a Napa #447 is needed if you are replacing a 10 bolt.(Bowtiered & Beast388). A good driveline shop will be able to help you on this, or call Steve at South Bay Drive Line (408-995-6000) who seems to have every U-joint memorized and is cheaper than most mail order outfits. Tell him Phat zakk sent you. He'll then know your working on a Blazer of some sort.
E-brakes are on a case by case basis. Mine work, but they aren't as tight as they used to be. Adjusting them is a fo-sho!
Other issues to consider:
The 14BFF is also affectionately known as the land anchor. while doing your swap it is a good idea to lop off 1" of the lower lip. this leaves well over .3" which is plenty of metal. Some have gone as far to make the 14BFF a 13BFF and turn down the ring gear and then plate the bottom. Remember: Ground Clearance: every 1/4" counts!.
Also, the 14BFF is an 8 lug axle. It can be converted by use of adapters (one company is Echobit.com) to make it 6 lug, or you can swap 3/4 outers from a K20. You deiced what is best for you.
And with that, I'm going to treat myself to a frosty Diet Coke. Good luck.
