I have a 95 dodge ram 1500. It’ll only spin 1 tire. What rear end would be the easiest swap that will spin both. Currently has Chrysler 9.25

 

You need to add a limited slip unit to your existing 9.25 rear. Once that's done, it will spin both tires, as long as the clutches in the unit aren't worn out. Luckily, replacement clutches are readily available. Dodge 2nd gen SST and Off Road Edition trucks typically came with limited slip 9.25 rears.

 

It was also an option. And it seems it was a popular one at that. It may have been part of one or more of the heavy duty/plow packages as well.

You can find 9.25's in the junkyard with an LSD. Probably swapping the whole axle would be cheaper than having one installed in yours....

 

The Chrysler sur-grip will do it but only once one wheel starts to slip and there is a torsional difference. Just rotation one axle by hand won't always lock the rear axles.

 

I would think the clutch-style LSD would have enough friction, that with the trans in neutral, turn one tire, and the other tire should turn the same direction. The GM Gov-Lok, on the other hand.... was an open diff until there was enough difference in wheel speed for the governor to lock 'em up.....

 

All the limited slips i had(from back in the day) would not allow one tire to move. Both the clutch and cone style acted the same way. If the clutches are worn i could see this happening.