Replacing brake calipers

Hey guys, new to the forum but had a couple questions. So I have an 82(?) maxim 650, I’m currently in the process of converting it to a scrambler but have run into the issue if changing the front brake pads. I’ve read in another thread that making them fit can be difficult and can require some Dremel tools, but I attempted this to no avail. I have purchased about 3 different pairs from three different manufacturers with the distinctive wedge shape, all specifically marketed for the xj650. Caliper is rebuilt, and also has stainless steel brake lines. If anybody has any information please share. It’s extremely nerve racking.