If the carburetor and intake manifold are on the right, or nearest the front side with the pull rope and has a real small intake manifold maybe 3/4 of an inch long... Then the muffler is on the left, or nearest the crank shaft side, That is an H50 five horse big block motor....
If the intake manifold is to the left nearest to the crank shaft, then runs down angled to about the middle of the engine where the carb mounts on, and the exhaust port is on the right closest to the pull rope.... That is an HS 50 small block 5 horse.