First, I am a lower speed (14-15) lower rev player. Been struggling the last few years to get my ball to hook. I use balls such as the DV8 Thug Unruly, Mastermind (original), Endless Nightmare, and the Ruckus Feud. Always thought the lower grit I used the more hook. Was wondering though if maybe I should use a higher grit to get more back end.

To add on, most of the balls you mentioned are very strong by nature, so that, coupled with strong surface, will cause those balls to use their energy up early and offer little-to-no motion down the lane unless you're bowling on a lake of oil. If you want more response on the back end, you'll need to smooth those surfaces out and/or add polish to delay things.

That being said, don't do that to all of them at the same time. Keep one of your current balls as your early-rolling, heavy oil piece, take the surface up on another one to handle mediums, and take the surface up and/or polish another to give you a third option/ball motion. With the balls you have, I'd probably leave the Ruckus Feud as the early-rolling, heavy piece, take the surface grit on the Mastermind up, and then take the surface up and polish the Endless Nightmare.  Of the three, the Endless probably gives you the best chance of creating a long and strong reaction.