To help a bit to identify them, OS FP, HP 40 , LA , ST G51 ST G34 are all Schnurle ported motors
Fox 35 Older OS 35 S , 40 H older Merco 35 are cross flow baffle engines
The typical port arrangement for Loop Charged motors are 2 intakes front and rear, 90 degrees from the exhaust port, and added is a boost port that is across from the exhaust port, So you ,most times . have 3 or more intake ports, 1 exhaust port
Randy