Here is my bike with a chopped pak and wrap around backrest. I spend probably 2 1/2 hours measuring, making a template, remeasuring, making a second template, comparing all everything before I finally mustered the courage to drill holes a brand new lid. But everything worked perfect. I picked the backrest up on ebay cheap because it had a broken bracket. I got a replacement bracket from the dealer for $9. I think that's the cheapest part I've ever got from HD. There was no need to adjust the bottom of the backrest. I have the Hammock seat and it fit really snug but I think works great and would definitely work with a stock seat.