He will receive the type that he orders.
The dual row bearing that fits a single row shaft is the Single Row Pro, which is a completely different bearing, requiring my Faultless tool to install. Read these pages explicitly and all of your questions will be answered:
Problem: IMS Failure. Solution: IMS Retrofit
Of course, if you have to inform the person doing this work of these things; that person is NOT the person that should be chosen to do the work.
The classic single row is still available and is not being superseded by the single row pro, as not everyone will be willing to purchase my faultless installation tool (749.00) thats required to install the pro kit.
Of course, we stopped selling these things direct long ago, and so did LN. They are available from our distributors.