Even the stock drum in hat parking brake that comes stock on the '99 and later trucks with disc brakes all around is marginal. If you hold your mouth just right when adjusting, it will work OK, but if you make the mistake of moving the truck with the parking brake on, even for a few feet then you need to adjust again. And if you polish the inner surface of the drum, then even readjusting doesn't work well.
Block of wood in front of tire. Hate to kick a guy when he is down but I am slow and weak so it is my only chance.? Adjust often and never forget to take it off is my advice. When I had my 99 six speed I would always block the wheels when the 5th wheel was hooked up on any slope the tranny and E-brake would not hold. My brother almost lost his trailer at a rest stop when truck and trailer went down the ramp after he got out.