should be fine with the 4 pin, if you were doing a 7pin with a brake controller then it looks like you need them
http://www.courtesyparts.com/Merchant2/m...ode=999T8-N5005

but here its showing the 4pin as just the wiring adapter
http://www.courtesyparts.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=CP&Product_Code=18399