I had a fully desmogged 2F in my '73 40 but ran the early 2 barrel carb and early vacuum advance distributor. It ran great and had so much more power compared to my stock 2F in the FJ60 with all the smog gear intact. They felt like completely different engines. (Of course, the 60 weighed almost double..) I lived in the rockies at the time and climbed the passes well. Only issue I ever had was occasional vapor lock in the fuel system. What all would you need to retain from the 60 gear to keep the HAC functional? Getting rid of all that vacuum spaghetti really simplifies things.