Reverse tranny skip Dakota SLT 5.9

I've got a 2001 Dakota 5.9 with a dual exhaust, when I put it in reverse and back up slowly it's fine, but when I sort of punch it & back it up, it seems to chunk or skip a little. Is it a rear end problem or am I losing my reverse gear in the tranny. I want to upgrade my spider gears or put a new posi in, would doing the upgrade fix the problem. I'm a new owner and with the power of this thing, it could have been abused. I got such a good deal I'm prepared to do what it takes to make everything right. Everything else is real clean and man does it Haul Butt! It even has leather and came with a gullwing tonneau hard cover. Please let know what to do. Let me know any other performance upgrades that I can do to this vehicle. Thanx Dakota5.9

if the whole truck bounces when you punch it in reverse and the wheels start to spin thats normal, you probably have a dodge trac-lock rearend, and its posi trac so the hopping is juss the rearend doin its thing, nothin to worry about, my 02 dakota has one and it does the same thing, any vehicle with a posi trac rear end does this

That does sound about what it is doing, otherwise I'll just keep having fun punching it forward, I was testing it on the Highway and at a certain speed, I won't say what speed, but the wipers start to vibrate, I guess I'll get one of those wiper gaurds, probably help with gas also, if I would just stay off it, oh I can't! help me! Maybe the newness will wear off.
Thanx for the info, Dakota5.9