Quadrajet's are great carbs., and can be tuned to handle big hp. I'd stick with it as your planning. Because of the small primaries, off idle crispness is much better than anything else when tuned right. They used 3 basic choke styles. Hot air style that had tubes that ran from the intake to the carb mounted choke, divorced style like you have that has the coil mounted to the intake, and electric that requires a sending unit mounted in a water jacket (usually in the intake or thermostat housing in the automotive world). 165hp from a smog era 350 is about right. Everything back then was wimpy. Take my old GMC camper special I had. Had a BB 454 with a m4mc (modified modified and with a hot air style choke) Qjet that was only rated at 245hp. That's awful for a BBC. If rebuilt correctly you could easily hit 250+hp, and can be done fairly cheaply.
Did you check bearing clearances with at least plasti gauge ? If the mains are to loose you will lose oil pressure when warm, and rods, well that will be self explanatory.
Did you check piston and ring clearances ? Ring gap should be .004 -.005 per inch of bore, but if you installed new, use the manufactures specs.
As far as cams go, you want something that has a power band from off idle or 1200rpm to 5 or 5500rpm, about 106 or 108 center line, and no more than 268-270 advertised duration. Lunati and Crane make great cams.
Another good option is to get a late model roller cam engine as previous mentioned, and opens up a whole new field with the variety of roller cams out there. Just using a roller cam will of a similar profile will give a small power increase just from eliminating the drag of the lifters. The nice thing with roller cams is more lift while maintaining a moderate duration.
