Can CAM and crank timing be off a tooth or so and still run but rough?

I have a 305 chevy small block timing mark 12 oclock, but the guy that rebuilt it put a chrome timing chain cover on it wit timing tab in 2 oclock position. After I checked compresion 130 each cylinder, found tdc and set timing on distributor, change intake and carb gaskets, adjusted valves it runs better but low vacuum 6 inches and hard power brake pedel at idel, it in a 63 chevy pickup and the old 305 ran with plenty of vacuum and sooper smooth idel. Can the cam and crank timing be off let, s
say 1 thooth and still run but rough idel in drive and low vacuum?