1982 GSL drift car
 

I have a 99% stock 82 gsl. I'm looking to turn it in to a drift car. I know the basics. But I would like some advice from someone that knows what they're doing on where to start. Thanks!

See this link for the setup on my 82 GSL.
https://www.rx7club.com/drifting-226...1027464/page2/

wheel adapters and bigger wheels so you can run a more popular tire/wheel size. stock fb tires are getting rare

As long as you're rockin a 12a or even an n/a 13b you're not going to need any tires bigger than 185 13's.

taking out the rear sway bar will give you a little more wiggle room before the axle binds and you spin out.
The stock suspension handles things pretty good as long as it's not worn out(bushings, shocks, etc) and if it is, it'd be a good idea to be freshened it up anyway.
This is me a few years ago. T2 swapped, but other than tokico blues, stock suspension.
Attachment 669755

And then this last weekend with re-speed coilovers w/camber plates.
Attachment 669756

Suspension helps, but learning with what you got and easing into more is better in my opinion. I'm using the stock LSD as well.
Finding someone to ride along with you can be a huge help when starting out too.