Feel like 360 should have more power

Are you sure that you have a 360 in that car and not a 318 with 360 heads on it? Since it seems that you just bought it anything is possible. I would expect a low compression 318 with 360 heads to have cranking compression like what you are seeing. Have you checked the block to make sure that it is a 360? 100-110 lbs seems really low to me. A stock 360 should have at least 140 lbs, unless that is a very big cam, something is not right. Could be as simple as you are loosing compression through the rings or valves, a lot of times an engine that is worn will have a substantial variation between cylinders, some will be quite higher than others. The variation on your engine is within 10% which is totally normal. The cam could have been installed retarded and that is what you are seeing. An engine with 100 lbs of compression will never make any power, it will be a dog.