Not enough radio volume

[vince1]

I put in a Classic Industries reproduction type radio and put some speakers mounted in home made boxes under the seat. They are just cheap speakers bought at Princess Auto, what I call our equivalent to your Harbor Freight. I am only using 2 of the 4 lead pairs, probably the left and right rear. At this moment I don't know where or how I'll get the front ones mounted.

It seems like the volume is only about half of what it should be. Just idling sitting in the cab the volume is set at about 80. Maybe someone could clue me in as to what ohm speakers I should be using and what effect they have on volume and etc etc for the anticipated questions that have not yet come to my mind. Thanks for your help.