SquareBody Fanatic

I have an issue with my acceleration on my 86 K20 manual with a 350. At idle I have 15 inch pounds of vacuum (I’m at 7,000 ft), when I start to accelerate, in idle and gear, everything is fine until I hit maybe 2-3,000 rpm (no tach or rpm gauge on dash) the car bogs out. Vacuum drops to less than 5 inch pounds (manifold). I have added carb gasket, replaced rotor, cap and coil, ICM, Fuel pump. All of these went wrong at about same time as acceleration issue. I have a Rochester carb which I had taken apart and not rebuild but cleaned with carb cleaner. Changed ignition timing to 10 degrees BTDC base timing. I have deleted smog system so the only thing hooked to manifold vacuum is carb and PCV. Have not actually removed components just removed from vacuum set up. I have checked spark with inline tester. I have also tried to search for vacuum leak using carb cleaner with no luck. Gas mileage is terrible and runs rich especially when throttle hogs down. My top speed is maybe 50 in 4th gear. It also backfires when letting off throttle. My next step is to replace intake gasket, which I already purchased. Any other things that could cause this issue? It makes me scratch my head because at idle it’s fine except it does idle high sometimes and won’t idle down except randomly. Also as a side not this all started to happen right after I replaced clutch and clutch hydraulic system (so new master, slave and lines). Spark plugs are definitely showing signs of running rich so I need to replace those but don’t want to do so until I fix the issue. Any help would be much appreciated!