65 GMC Front Hub Riveted to Brake Drum

[millspec]

Just like I wrote, I have a 1965 half-ton 2wd with single master cylinder pump and pray manual brakes. I was rather surprised to figure out why I couldn’t remove the brake drums on the front brakes.
At first I thought they were just stuck, so I tried backing off the adjusters. No luck. So, I decided to try removing the hub with the drum by removing the dust cap, cotter pin and nut. It came off and to my surprise, the hub is riveted to the brake drum in 3 places!
Of course, the drum is worn, so I need to replace it.
I have looked in the factory service manual, but haven’t been able to answer the questions why and can I drill out the rivets and use a regular brake drum?
The NAPA 440-1071 brake drums seem to have the extra holes for the rivets, but must they be used?


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[lizziemeister'sV6]

You don't need to rivet the front drums to your hubs. Your back drums are loose. What you do need to do is to get the proper drums for your GMC - Chevy drums are not the same as GMC. Lots of parts stores will tell you they are the same - they are not. GMC's have an offset near the lug bolt holes. Take your old drums to compare when you get new. Hopefully other GMC owners will agree with what I said. Any comments?

[millspec]

I’m not sure what you mean by offset. I compared the drum from NAPA to the current one. The hole in the center for the hub is larger on the NAPA version in order for rear axle fitment. When I place it on top of the front hub upside down, there’s about 0.125” clearance around it.
The picture shows some tabs that are bent in which the NAPA part doesn’t have. I’m not really worried about those, but is it okay for the hub hole to be larger than the hub center?
If you happen to know the correct drum part number and a source, I would greatly appreciate it.


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[millspec]

IMG_7224.jpg


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