I am just curious Where abouts do I adjust the advance on my 308 GTSi.
You don't. The ignition is solid state. Each distributor has it's own drive box the reads a crank signal and vacuum, then sets the timing to the programmed value. So to crange it, you need to install a new ignition system that can be adjusted. Electromtive makes one that is a multi-coil waste spark system. Also a haltech EFI computer can read the OEM crank signal and fire either your stock distributors or multiple coils the same as electromotive, but requires you to buy the coils and module separately. Another option is to install a mechanical distributor, but personally I perfer the electronic options