Yeah, that's the point I'm trying to get across. At minimum, the original poster needs to replace those drums, adjust the brakes to suit the new drums, and hope the pedal height and firmness stays "good".
Frankly, I don't think the 254mm (~10 inch) rear drums are worth the effort, especially on a K1500. When it was me, I scrapped the whole axle in favor of a 6-lug K2500 axle of the same gear ratio: Not only is the 9.5" ring gear axle enormously stronger than the crappy 8.5" ring gear axle, but the 11.x inch Duo-Servo drums work three times as well because they STAY in adjustment, unlike the horrible 254mm Leading/Trailing drums.
Frankly, I don't think the 254mm (~10 inch) rear drums are worth the effort, especially on a K1500. When it was me, I scrapped the whole axle in favor of a 6-lug K2500 axle of the same gear ratio: Not only is the 9.5" ring gear axle enormously stronger than the crappy 8.5" ring gear axle, but the 11.x inch Duo-Servo drums work three times as well because they STAY in adjustment, unlike the horrible 254mm Leading/Trailing drums.