Well, if the lock is not a preinlet one you may be able to put it wheere ya want it, and you want the vent hole at the top edge of the pan horizonally, and center of the pan vertically looking. If it is already preinlet & you have to put it where it is, sometimes you can shim the barrel up if necessary if you have not removed any wood at the yop og yjr ntrrvh/tang area & have some extra wood there on top.
And if it is inlet & no wood to removbe, the vent will be where you drilled it, unless ya plug it & redrill & etc.