Low T/A

[band1t]

Hey all,
I need some Info on 2 gens.
I have a 1979 trans am riding on 17s and on thing I hate is the gap in the wheel well showing.
so instead of buying a 18 or 19 in the rear I was thinking of lowering it.
Here are my questions if what can I get away with??
If I went a 1 inch or 2 inches would I have to cut the tunnel in the floor for the drive shaft?
Also would I have to change to a glass pack style muffler?? the ones I have on the car scrape when I drive through a "dip" in the road or up a
steep drive way.

If you got pics of your bird or camaro lowered please share them.