If you really think your cam is installed wrong, take off the valve cover rotate engine and watch the intake and exhaust valves. When rotating the exhaust valve will open then start to close, keep rotating slowly and the intake will begin to open, when the balancer gets to zero this is the overlap period, basically both valves should be open and by the same amount. Exhaust closing and intake opening. If one is open a lot more than the other your cam is out of phase. If you use a dial indicator you can check for advance and retard, if the cam is open a few thousands more on the intake it is advanced, the exhaust open more it is retarded. If you are at least a tooth off, you should be able to see the difference with your eye. And when setting your distributor, remember your coil does not fire at zero TDC it fires 10 to 20 degrees before TDC.