.....Why are my tires spinning the wrong way?

[rawfuls]

Well, after I guess... stripping my rear diff, I purchased a new 16.8 EMaxx diff, off eBay...

After a couple hours of wrenching (never went this deep in the maxx, replacing something, so taking things apart was new....) I finally replaced it, my CVDs, everything..
Of course, nothing goes according to plan for me..
Today, I take it into my front yard, for some test bashing?

Anyways, I plug it in on my porch..... I lift it up (I check the trim, and everything upside down, so it does take off, and break my leg, and a door... )

Anywho, when I push forward, the front end goes forward, while the rear end goes backward... Needless to say, the maxx goes NOWHERE.

Could it just be a case of reversing a motor? Or did I put a front diff in the rear, if possible?

****Well, on a couple other forums, I received a answer on a couple other forums, would the problem be that the diff is flipped the wrong way?