I just accuired a 1st gen 84 gsl-se and reallized I'm pretty down on money, and I was wondering what would be the best bang for my buck? I'm open for any opinions on this! I've already reamoved the 3rd cat on my 13-B.

 

Making sure everything is in good shape first, replacing what is marginal is the best way to start a new project. After that:

Exhaust.

Header, presilencer, muffler.

Then:

Tires. If you live somewhere with no rain, R compounds, otherwise, maybe the sumitomo's. 13" performance tires are getting a little scare.

 

ummmm.....he has a GSL-SE.........14" wheels

 

1. convert to a cone filter intake. cheap and easily accessible from ebay. fabricate a heat sheild for it ($20)
2. rb exhaust. ($647)
3. electric fan ($75 for a new one, low as $5 for a junkyard)
4. sumitomo sirxon 205/60/14 tires. cheapest hi performance tires i have found. these tires grab the road and won't let go if handling/autox is your bag ($275 for 4)

I have this setup and my 84' se will run with cars in the low 7 upper 6 0-60 range and will out handle all of them.

 

tires tires and more tires. You'll find a lot of improvement with this.

 

Welcome to the forum. There is great amount of very good information and some of the best guys/gals around to ask for help.
Personally before I'd make any modifications to the car, I'd start with some basic maintence. Full tune-up....plugs(NGK), distributor cap, rotor, plug wires, air filter, fuel filter. Depending on previous owner and what he's done...I'd change coolant, trans fluid, engine oil and filter.
Removel of the 3rd convertor is the same convertor that has the 5/6 port split air pipe attached to that opens the Auxillary air ports/sleeves at higher RPM's. Make sure that is still intact and operating or you'll lose some upper end power (unless they've been wired open). There's some good threads about 5th/6th ports here. Do a search on those since they have a tendency to get carboned up and stick.