I am in the process of gather materials for a sas build.  I am new to the 4x4 build world and need some help.  I have a 14 bolt for the rear end and will be trying to pick up a dana 60 for the front.  I know that I want to run 4.56 gears, but I do not know about the lockers.  I do not know what type of locker to go with since the truck will get driven almost daily.  I know that when I put the truck in 4 wheel drive I want all four wheels turing.  I just what to make sure I do this once and do it right the first time.  

Replacement lockers (like Detroit's and others that replace spider gears) Can be a heart attack on slick pavement in a daily driver and not a lot of fun either on a slick hillside/bank that you are transversing. I would suggest a selectable locker that you can lock on demand like a ARB or Eaton E-locker. The ARB is offered for your 10.5. BTW, even open diffs send same torque to all wheels, nor more, no less. They just cannot send more torque to one wheel than other thats all.  

Will towing effect the selectable lockers?  Do they work like a normal diff unitl they are locked?
I am very early in this build and I am having to plan out each move due to money concerns.  

The ARB air locker works just like an open diff when unlocked, I suggest going with a Detroit in the rear and an ARB in the front. Detroit lockers only lock when you hit the gas pedal. The onyl problem with the ARB air lockers is the expense, they are around 750 to 800 just for the locker, and you will need an onboard air compressor as well.  

offroadnut36:
The ARB air locker works just like an open diff when unlocked, I suggest going with a Detroit in the rear and an ARB in the front. Detroit lockers only lock when you hit the gas pedal. The onyl problem with the ARB air lockers is the expense, they are around 750 to 800 just for the locker, and you will need an onboard air compressor as well.

Bad idea. Detroit's and replacement lockers that do away with spider gears are a very poor choice for towing and not recommanded for towing at all. Also consider this, serious off road machines like end loaders, back hoes, farm tractors, earthmovers and such DO NOT have Detroit style lockers. They have selectable lockers or open diffs.  

for lockers i would go with a auburn ected up front and whatever selectable locker in the rear  

Yeah i forgot you were towing, Snoman is right. A limited slip, or a selectable locker would be best for towing.  

Arb air lockers work great. I own one myself. Bought it because of ice. Posi on ice and you can die!! Arb up front and a limited slip in rear will work. One problem with limited slip on clutch style and heavily loaded/towing is wear on clutches. Ran a trac lok and a power lok both worked great but maintenance and clutch replacement is the only issue. The power lok can be repaired in drive way and not really a hassel. Trak lok's can be a pain to install new clutches. I usually just took to my local shop. Power lok's simple. Never ran anything else so can't help you out with anything else on limited slip clutch style.  

It really depends on the type of limited slip you have as far as if it wears out sooner towing. Governor control GM G80 GovLocs have no issues towing and none of the gear based LSD's have any problems towing either (The legendary OshKosh plow trucks have used gear based LSD's for well over 30 years now) By only concern with a ARB would be the possible of ice in air line in extreme cold blocking its function. I would go with a electrically controlled locker today and it is easier to route and repair wire (if need be) controlling it too.  

One of the tricks I do on air lines is run stainless tubing near headers to absorb heat which help keep lines thawed out. I've never had one freeze yet but I do run a synthetic redline oil in diffs. Synthetic oil in everything for cold weather. -20 to -30 below is not uncommon in wyoming in winter. My truck has to perform in these elements and their are a few tricks. On the gov lok's they have that little gear that spins internal and they give it up a lot. I have two axles sitting in my spare axle pile and both gov lok's are dead. Was told the bearings are different and not able to install different carrier??? haven't researched that info yet. Figured I weld it up for mudhole running. I like the idea of limited slip with no clutches. I change out clutches about once a year after a hard winter and many snow runs. Power lok is a bolt together case and easy to repair. need to get off my but and spend some money and upgrade! O'yeah one year near Big Piney wyo is was -41 below Its really sucked huge. Had to work in it and couldn't even touch anything 2005 winter.  

I lived in MT for a while in 90's and I saw it crowd minus 50 a few times where I was and get to minus 40 several times. I found that not even off the shelve SYN lube does much good at those temps. I used to add kerosene to power steering and a pint or more to automatics, several oz's to a manual gear box and Tcase too. It helped a lot. I would use dual block heaters too on my burb when I used it. It had dual heaters (front and rear) in cab too. Generally though when it was extremely cold I did not drive 4x4's I had unless I really needed them as I use FWD cars as I found that with a bra on front blocking off most of airflow thru engine compartment that they warmed up nicely in extreme cold and ran like it was much warmer out as all drive compoments were keep warm in a group until a 4x4 where many were down in the cold. I remember one 100 mile trip I made in my burb when it was close to minus 40 early in morning well before sunrise. While I had a cover on grill to keep engine toasty and I was not cold in truck the Tcase and drive axles were in the cold and even in 2wd and syn lube in Tcase and rear axle it felt like I was dragging a anchor when cruising. The faster you went the more you seemed to feel it. BTW, on rear axle question, if it is a 14 bolt 10.5, GM change the bearing cage for pinion and a bearing in it around 89. There was no change in gears or diff from it and new style cage will bolt in a older axle.