This might sounds like a dumb question, im new to all this.

I have a 87 firebird formula, with a 305 crate motor with a qjet collaborator.
I didnt know if there were some add ons, or easy things to replace that couldd add some performance and or better gas mileage. I have lots of friends who know about cars to help, im just now getting into to doing this kind of stuff.
Maybe a different carb, or getting mine tuned?

 

There's no carb that gets better mileage or peformance than the quad - keep it - anything aftermarket is going to decrease both performance and mileage.

Swapping out of that 400 Turbo tranny (3 speed) back to a factory 700R4 (4 speed with locking converter) will help your mileage tremendously - and there's no way any 305 'needs' the strength of a TH400 tranny.

 

The guy before me swapped the trans, i have no idea why.
I have a friend with a 700r4, hes got a 350 in his camaro he might wanna trade.

What about tuning the carb

 

keep your hands off your carb. theres nothing you can do to help your situation without spending money. you have a low rpm, low hp, small bore, wimpy cam, that transmission has a low first and 2 really tall gears,

pretty much without spending a ton of money your SOL,

anything you do to that engine is a waste, you could trade for a th350 and swap your rear end gears and get a ncie seat of the pants change

 

Do the 700R-4. First. This would be the best time to install a 2000-stall torque converter. Then start with the cheapest, easiest stuff: what's the axle ratio? If it's 2.73:1, then get a 3.42:1 axle, like from the '85-'92 V6 / automatic F-cars. Huge bang for the buck.
Back to the engine: start with a high-flowing exhaust system, and headers. Then a dual-snorkel air cleaner. Next is an Edelbrock intake manifold. That would be the best time to add a moderate cam. Maybe something like Comp's 12-388-4.
If you do all of that yourself, it's about $1,100, plus the 700R-4.