Garage heat

I'm in the Chicago suburbs too. Didn't want to worry about open flames in the garage and wasn't planning on running all the time. I decided that the few times I'd be out there, I'd pay for the electric. Still haven't installed the heater or insulation. Decide what you want to do in terms of codes, permits, etc. and nosy neighbors. Ended up upgrading the service to the garage to 240V 50A (had the wire). Compressor, lights, welder, no problem. Probably can't run all of it at the same time when I install the heater unless I turn things off when not using them.

The way I read the NEC code, with RIGID pipe (not direct burial, not PVC, not regular conduit), you can get away with 6 inches of burial. Might even check to what size pipe may even be run out there already and pull new wires. I tried too but someone used and elbow instead of a sweep bend and couldn't get the wire #8 I wanted to run through it.

Separate building separate the ground and neutral and drive a ground bar. Wasn't too bad to dig the 50 ft to my detached and I'm way out of shape. Run as large of pipe that you can afford work have tools to work with. You an always pull heavier wire later. I ran 1" pipe because I had that size masonry bit and pipe dies. I think I can run 3 #3s for 100A according to the conduit fill charts. If uncomfortable with electric, talk to the electrician about maybe you digging the trench, that's the labor intense part.

Just reread your post. You mentioned fuses. Might want to check you service panel/drop too. When I bought the place 10 years ago it was still a 60A fuse panel that was already out of room and a few questionable practices. Insurance company wanted it upgraded before they wrote it the policy.