Installed the belt drive and for some odd reason it keeps wanting to come off. Had the car running for like 30 second and it looked like it did in the pic. Every time I crank it comes a little bit off. I have it aligned on the pulleys when I put it back but it keeps moving forward. There are two covers for the alternator pulley one on each side that keeps popping off. I think I might just have them welded on. Has anyone had this problem before?

 

It could be walking off the gears because the tension is too tight.

 

Your top pulley is not flanged (your first pic shows a flanged pulley), a straight toothed belt like your Gilmore set-up needs something keep it from sliding off. Timing belts, a lot off time don't have the flange on the timing gears but, somewhere in the chain of pulleys, there is a flange to prevent the belt from walking off. If not more than one.

 

Ill loosen it a little

 

I had taken it all off because they kept coming off and when I went to put the pulley back I must have forgotten to put the back one on that's my mistake. Regardless the front popped off in the pic, it was an after pic.