FYI, small pattern axles, no subframe connectors and torque boxes shouldn't be a deal breaker. Dad raced my car for 10 years without any of it. Would it have been better or stronger, yes, but it is done often enough that it shouldn't stop the build or driving it. I guess it depends on the individual build. I just swapped the rear axles and brakes on my car this last fall. Still small pattern on the front. I am sure the OP will not have the HP to worry about breaking stuff much.
