High offset wheels benefit you by lightening the total weight of the rear end as an assembly in the car. If you have partial skirted wheel openings like a Dart, you really do not want long axles. Trying to get a big tire out with a high offset wheel is bad enough without adding to the drama. Wheel offset is of no concern with strength. All the fastest cars have the wheels offset. Heck, look at any vehicle with dual wheels. They are made for heavy loading.