Just to clarify, this is an external line. There is no internal line.You need to have a way to drain the cavity. If the engine is factory fresh, there normally is a drain tube from the front of the engine to the rear govenor pad. and the rear governor pad has a special cover with a slot milled in it. if you have this, no need to punch. if not, need to punch.
Just beware that there are two different plates that could be installed on the govenor pad. One has the slot mentioned and one doesn't. If you have the flat plate without the slot machined in it, you need to pierce the rear crankshaft plug. Also, if you intend to remove the governor drive and associated plumbing to save weight, you will then need to pierce the rear plug in the crankshaft.
Good Luck, Mahlon