Delco CD player

In general, this is a difficult if not impossible proposition.  Most factory "premium" stereos with seperate in-dash components MUST have the full compliment to function properly.  That is not to say it can't be done, it's just that it is difficult.  You'd have to start with the factory wiring diagram for that exact model and then you could propably figure out how to power it and what wires carry the low level signal output.  Then you could tap the low levels and solder in a set of RCA's and probably connect these to the new tape deck.  Some factory systems (most notoriously those with the BOSE name on them) are pretty useless unless you use them as designed.

A simpler and better solution is to buy a new double DIN system if you need to keep both the tape and the CD, in my opinion.

Good luck!

It would be easier as well as a better match up to go with a all in one unit.

GM loves to be proprietory with the electronics.