If it was like my RV 7, only a z braket bolts carries well, and is the root of the wing, the rest carry platenuts riveted and access is across the bar where you work comfortably ...
Eventually can roughing tube 3/8 leaving a very thin wall, which is used in many places. The proper torque for AN3 bolts can never breaking the tube. Anyway, in this particular case to do a little more force because new platenuts.
RV-7 builder and pilot