Got a GS here and am fixing to rejet. Seen recomendations for rejetting with exhaust and intake but what should I use with Pod filters and a heavily drilled stock exhaust? Can I pull the stock baffle out of the exhaust?

better to just weld on another can from anything
drilled sounds horrible

2mm shims under the needles
1 size up on the pilot
1-2 size up on the main
air correction screws 2.5 out and adjust from there
of course this is for the older carbs without mid ckt

Any benefit to plugging the slides?

not with stock needles

you understand that a 5% increase in power is less than 2 HP.......

almost unable to notice with a butt-o-meter
the bike will perform and transition better

spend the 30-40 bucks and get a 15T and 14 T c/s sprockets....the BUTT-o-meter will notice this mod

Speaking of gearing...would you recomend 1 down and 2 up in the rear? What length chain will i need?

I recommed 2 down on the front and pull the wheel back   $20 buck mod
but if you really want to buy another 40-50 buck rear sprocket...go for it

Well I am about to put a new chain and sprockets on anyways.

1 down in the front is about  =  up 3-4 in the rear

if ya spendin money and want life...
calc gear ratio and then re calc for 17T front and....rear
you will get better chain life out out of the bigger diameter C/S sprocket