I just picked up a 3 hole model 7 FS locally (an hour ago) and am looking for a base and rings. I'd like to use talley lightweights, but will have to drill and tap a 4th hole. My questions are:

Is there enough material in the receiver for the 4th hole? What height talleys would I use for a bushnell elite 2-7x32? (I'm thinking low)

Thanks for the help.