Finally got a Dart, been sitting a while...

Pulling the pan is a good idea it could be rusted inside crank, block, rods, My friend had a 12 HP briggs that was rebuilt and then sat for a couple years and he put oil in it and it wouldn't run so I got it and some one put in new valves and never grind the tips them so they wouldn't close all the way, anyway all that cranking wasted the new rod because the crank was rusted.