Truck pulls right and seems to be getting worse

[87highsierra2500]

hey guys, i have a 1987 GMC High Sierra 2500 I've owned it since 2011 and its always had a slight pull to the right, but lately its been getting worse and worse. All the front end parts seem tight, I replaced all for ball joints last fall, both tie rods are tight and the drag link ends feel tight as well, and I replaced the front leaf springs a few weeks ago for ride quality issues. It also pulls pretty good to the right when braking, feels like the right front shifts back when I'm stopping, I've never felt anything like it and I've been a GM automotive technician for 11 years! The front brakes seem to be working equally, I measured the pads and they are the same on both sides. The rear brakes also seem to be operating properly, have the same lining thickness and the distance from shoe to drum surface seem to be good. I'm running out of ideas and I really hate throwing parts on something if its not going to fix the problem. If any of you guys can give me any ideas or tell me something I'm missing it would be greatly appreciated!! Thanks,

Josh.