If you aren't using all of the original emission control devices it will respond well to a slight recalibration for the crate 350 engine.
I would recommend one of our SR rebuild kits, jets, and our fully tapered 50C primary metering rods and new power piston spring.
Also check the pull-off to make sure it holds vacuum and the electric choke to make sure it works. I always replace those items here during a rebuild as most are at least 30 years old and usually the first thing to give trouble once you place the carb in service.......Cliff