I would not hack the dash to install a CD player,why do that when they are nearky obsolete??..I'd keep the CD player in the console ..the dash is only "virgin" once!...
If you bought an original Delco AM radio,was it from a truck like yours,in the 67-72 vintage??..some CAR radios look identical,but not all have the "staggered" shfts needed to fit some vehicles--one shaft sticks out more from the case than the other,it is offset some-other radios had both shafts "even" with each other..
I have a Delco AM radio that came out of a 67 Impala that has the offset shafts,and I still have a factory Delco AM/FM/CB in dash unit from an 80's GM car (Caddy I think) that I had on my 82 K2500,I think it would fit older trucks--I replaced it with a later cassette player radio--one channel on it doesn't work,it still plays out of one channel fine,probably just needs an output transistor replaced...its a cool radio,you can monitor CB channels while listening to the AM/FM radio,when a CB signal comes in strong enough it squelches the radio and lets the CB be heard thru the speakers..