Audio Systems: AM doesnt work, car stereos, tunners

Question
Thank you for telling me how test for whether or not the antenna or the stereo was at fault for not receiving AM on our Audiovox gc-600.  It turns out that it is the stereo.
Now, is this something we can repair?  How?
The hole for the radio is very large, 7-7/8 X 4-1/8.  Today's market doesn't make car stereos that large and I am having problems finding a adaptor kit for that size.  Any suggestion?

Answer
the radio tunners needs to be replace they run in the $50.00 to $90.00 for parts only and some one needs to repair or install the new tunner
if you  want to replace the radio  call andy 407-933-1065 and ask him for a 7x4 radio they have some with the brackets and trim around the face it will fit your opening hole
good luck