Just my opinion but the last thing you want to do out there up against the side of the valve cover and a cast CV carb is hitting on a manual impact driver.
The bolt doesn't go into the valve cover. It goes into the cylinder head.
But, I would try a big screwdriver with an adjustable wrench on it for torque first. Press real hard on the end of the screwdriver. And I wouldn't put that stuff back on either.
Yeah other then having to fix the carb leak, it unfortunately had a hyper charger on it as well. I hate everything about a hypercharger, don't look good on anything. Hopefully whoever put them on last did not Gorilla them on. Find out tonight.