Your glovebox keys and ignition can be keyed the same provided it is an original ignition switch. General motors used about 20 different key patterns over the years. If your glovebox key will fit into your ignition, have them keyed to the ignition key due to the fact it is much easier to accomplish.
As for the gas cap, that's a differnt story. Gas caps that utilize a key have been made primarily by Briggs and Stratton and are not compatible keys with GM
If you have a good locksmith in your town, they will be able to handle your problem.
Good Luck,
Dr. Mike
