On asphalt, you can actually get both to spin with an open diff. They don't send power to strictly one side. There is no drive side. It sends the power to the side with the least amount of traction. On a turn, this would be the outside wheel but when driving in a straight line both actually are getting power unless you have something like two different sized tires. What usually sets only one to spin is weight distribution. You can get a new factory carrier for $215 directly from Ford if I remember correctly. The downside, you have to start using the friction modifier, need to reset the ring and pinion (special tools are required). Getting another axle is just too much of a pain because even if you did get a used carrier, you would need to reset the ring and pinion unless you just did an axle swap. Cheapest solution is actually a lunchbox locker, but that is too aggressive for many people.

 

I just want something to fool around in the grass or gravel when I need to lol

 

Ford Racing used to have the Trac-Loks for $215. But like I said, in the end it will probably cost about $350. You can pickup a lunch box from either Summit or Randy's Ring and Pinion for right at $330. I believe they are much smoother in automatics than they are standards.

 

That isn't gonna eat my tires off tho is it?

 

What about a limited slip locker

 

No, lockers differentiate. What your thinking of is a spool. Lunchbox Lockers keep the OE carrier in the truck while just swapping the spiders. A new carrier will be about $100-$150 worth of work just to get it in. Here are your budget options.

Ford Trac-Lok (OEM):
http://www.fordracingparts.com/parts...rtKeyField=225

Aussie/Lockright Lunchbox:
http://www.aussielocker.com/index.ph...-xd-48831.html
http://www.summitracing.com/parts/PWT-1822-LR/

Powertrax No-Slip Lunchbox:
http://www.summitracing.com/parts/PWT-92-0688-3108/

There are some more LS options but these are some of the more popular traction setups.

 

The Ford one says for off-road use only is it the same for the others?

 

Here are the differences between the differential types.
The GM Gov-Lock is the only one I've found that can get off the jack stand.

 

So which one would be best for alot of highway driving but yet still able to help connect in gravel and grass

 

Highway or city? I'll tell you exactly how that F150 in the last video drives. It has a Lockright in it for 5000 miles now. It maybe see's 20 city miles a month, everything else is highway. Since Sunday I have put 1450 miles on the truck, all highway. Gets a little more squirrelly on dirt above 50 mph and when I drop the clutch it engages a little more aggressively. Turns just keep your foot off the gas and it turns just fine.