I noticed when I tie on a weighted swimbait and reel it in, it likes to swim on an angle with its head dipped down or up slightly instead of swimming straight and looking realistic. Am I reeling too fast or too slow? Is it the type of knot or line I'm using? Do I need to adjust something? It is one of those storm wildeye brand swimbaits in 1/4oz. The reel being used is 6.3.1 gear ratio. It seems like the more expensive swimbaits I have swim straight on their own.

The angle of the line tie in relation of the hook, the kind of knot and where it is tied on the eye, retrieve speed, position of the rod and balance of the bait all have an effect.  A 90* line tie and a loop help keep the bait horizontal.  Most of the weight in the wildeyes are in the front of the bait which kind of causes the head to drop on a slow retrieve.

The line tie on those is fairly far back on the top of their head. If you tie a knot that will snug tight and slide it to the very front it will ride a bit more horizontal, but it will always point down a bit. That thing catches fish. Fish it really slow or really fast.