I have Vance and Hines Big Shots on my 90 FXSTC, and I am experiencing a lot of reversion.

Has anyone ever dealt with this issue before and how was it fixed?

 

Unless there's something wrong with the pipe or something plugging it, reversion comes from not enough back pressure. This comes from running too big a pipe or from no muffler. I assume you're running without baffles or with minimal baffles? The fix is to put a better set of baffles in. Unfortunately, a lot of us like our bikes as loud as we can get them. Nothing sounds better to me than open pipes, problem is that kills performance between 2000 and 3500 RPM.

You could try the lollipop trick. It will help some, but it's nowhere near as good as a good set of pipes/mufflers. Don't waste your money on the torque cones. The lollipops will do as good or better. BCT baffles makes a combination of squeezing the inside of the pipe along with lollipos which supposedly does even more without creating the "farting" sound of baffles.