turnswitch.com sells the correct replacement speakers for just about all 60's-70's Mopars.
They have the 4x10 with the correct small magnet so it fits , and the correct 8-10 ohms .

Greg

Wards Classic Car Radio Repair Specializing in restoration and sales of Mopar A B E body radios
We can restore YOUR radio usually in less than 7 days
Visit our NEW website..
http://www.wardsclassiccarradiorepair.com
gregward@mchsi.com
phone 256-852-0955