1966 dual master cylinder

A member here has a new master cylinder I believe he picked up for his 67 Barracuda he added disc brakes to and NAPA said it would work, BUT they sold him the wrong one and the one he has is for drum brakes. he has the correct master cylinder on his Barracuda now and the master cylinder that would not work he has and has offered to send it to me for My 66 Valiant so I can have a dual pod brake master cylinder =D>
He said it will work for my drum brakes and he said he thinks it's a large bore.
Large bore/small bore :dontknow: Does this mean all I will need to do is adapt to a small brake line with a reducer :idea1: He is giving it to me so I don't want him to waist his time and money sending it to me. I believe it is this one and my push rod on my single MC will work for me :glasses7:
http://www.ebay.com/itm/CARDONE-13-...pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr and this is the new one I put on about 2 years ago, http://www.ebay.com/itm/CARDONE-10-...pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr

Large Bore :scratch: Small Bore has me confused , Thank you for any help on this again =D> Yall have been great :notworth: