1972 Duster Build with my Daughter

Found NOS piston, rod and gasket sets on eBay. Rebuilt the “rebuilt”. What a hack job. Polished oil pump parts and plates, new pistons and rods, polished the crank. Filled with correct oil level, added R12 fill * 0.80 of R134a Mixed with the NOS expansion valve it is cold as hell and quiet at hell. What a battle.
I think all of my equipment is in top shape but it is a 1970 340 duster .
is the 1973 equipment any deferent than the 1970 ?
I don't think the shop I was referred to was wanting to work on a 1070 car.
I have r12 coolant but they didn't want to put it in.
I will try a deferent shop next week