Cd Player/Changer Question(s)

[76corvette]

I have a custom autosound mfg's USA-5 Cd Player and Changer for my 76 corvette which has the original Radio in it... I am about to install it. Just pretty much getting ready.. and I was searching and reading through cd changer/player posts and I came across Ala75Vette who had mentioned something about the L connecter and then putting in a 2 L connecter and said it worked better... Is there anything else i should look at on a 2 L connecter? (dont know much about audio cables and whatnot and I dont want to put in the wrong cable).. I am installing the cd player and changer and I have read that most people take out the bottom of the compartment behind passengers seat... I was wondering if anyone had good ideas or suggestions as to how to modify the bottom of the compartment area... Any Advice / Suggestions or Warnings about the installation before I take her out and put her back together? I really want to get this done tonight/tommorow (sunday)... Thanx in Advance!!