Is a GMC truck just a dressed up Chevy truck?

I don't know about now days but there were --in the day--DEFINATE differences in things like brakes. It's been too long to sit down and enumerate, and you'd have to get into rear axle, suspension, and brake catalogs to dig them all out, but in the day, a C10 Chev was for certain "less heavy duty than a 1500 GMC

Again, no idea if that is still true