55.2-59 Issues with rear brakes

[jeffs56]

Hey guys hope you guys can help. I’m working on my 56 Chevy truck and having issues with squeaking/squealing/grinding sounds when I press the breaks. I took it to the shop today and he said he thinks the drums aren’t true. I have a ford 9” that has been narrowed with brand new axles with 5x4.75 bolt pattern. The guy showed me the inside of the drum and it looks like it is rubbing. The guy that installed all this had to grind some spots on the metal part of the brake shoes which I thought was odd. The guy at the shop is saying maybe he didn’t cut the axles to the correct size causing it to stick out farther and having the brakes hit the inside of the drum. What do you guys think. I’m hoping it’s just a not true drum and be good.
Also would going to disc brakes fix these problems? Thank you