1981 to1988 gmc p3500 rear drum brakes

[lefty7845]

Can anyone tell me which parking brake hardware kit I would need for modifying my 1981 p3500 (no parking brake) to a 1988 p3500 backing plates? I have most of the parts, but the pins to hold the parking brake lever to the rear shoes are to short by almost 1/4". The kit that I ordered 18017743 indicates it will fit a 1988 and a 1981. I checked the old brake shoes, and they are also to short with those shoes.