Back in the day I think I remembered a snap in pickup roller assembly that would add a pickup roller to a normal MPC and later era truck.
I am aware of pick-ups that fit postwar plastic trucks, and snap-in pickups that fit 9050 style modern era trucks. There probably are snap-in pickups for later modern era trucks too.
If you specify a couple of trucks, I'd guess that someone would be able to tell you what to use.