i have a 1992 firebird with a 305 tbi engine and i was wondering what are sum unexspensive first mods that i should do to it to make more horse power

start with an open element air cleaner and full exhaust. headers and catback. then do gears and a posi

Define un-expensive? Less than $100 then go with a open element, adj. timing, cooler T-stat 170* or 160*. Check the Tech Articles on the home page of this site for TBI mods.

IMO the best first mod would be full exhaust(cat-back,cat,headers) with 3" y-pipe, 3" cat, etc. This would probably set you back around $600 brand new.

Open element air cleaner, $15 from Summit.
Headers and cat-back.
180 stat, not a 160 or 170, too cool, computer will hate you.
Now for the free things:
Adjust your base timing, 4 degrees is safe with stock exhaust manifolds, 6 or 8 is good if you've got the headers and open element done. That's just a figure from experience, play with it and see how you like it but don't go more without using a scan tool or winaldl to check for detonation. Detonation isn't audible anymore, computer hears it before you can and retards the timing to get rid of it.
Next free mod is the fuel pressure regulator. Make it adjustable. Get Summits 0-30psi fuel pressure gauge and t-fitting to check and set your fuel pressure. Be careful though, the cheap $20 gauges work great but are very sensitive to heat. So remember the temp and don't freak out if it changes when you pop the hood and it's warm!
Then after that, I'd make my own injector spacer which is basically a couple/few gaskets stacked on each-other. Then if you've got the resources, make your own TB spacer. While the TB is off, do the ultimate TB mods or have a member from this board do it for you mail order. It's like $40 to have somebody do it for you so either way it's inexpensive. Then once that stuff is done you're left with a choice to do either gears and posi out back or an intake manifold. Personally I would save up for the gears and posi. Once both of those are done I'd get an intake and do the Lt1 cam swap at the same time. That's all I would do to the L03, any more invested would have been better spent on a 350 swap. Just my $.02

Hey JPrevost who is it on here that will do it for $40? I've got an extra TBI that I could send and then just swap it out when I get it back.

I only know of a few guys that'll do it and I'll direct them to this post. There is a core charge though. So you'll have to send back your old TB. I would offer the service myself but I've got enough on my plate as is. Just try it out yourself. The trick with aluminum and using a dremel (if that's the only tool avail) is to remember it's a non-ferus material so it'll clog up sanding paper etc. The trick is to use some WD-40 to keep it clean. Really it isn't hard, just do NOT port it out down, just do the top and blend it down a half inch into the bore. If you feel good you could also work on the injector pod.

If you have a bench grinder the job is cake. It'll take care of those throttle ridges in a few minutes.

As far as the T-stat goes, maybe if you live in the north where it's cold it may act up, but mine didn't while i was in NY for 3 weeks in Dec. With a 160* stat I got .3 sec and 1 mph in the 1/4 and have had no drivability problems in the last 5000+ miles or so. To keep the temp down when idling or stopped I run the A/C, it automatically turns the fan on(yes I run the A/C in the staging lanes). I get ~23 mpg on the highway @80 mph.

These are just my results, maybe others have had problems with the cooler stats though.

With 3.73's, a 330hp vortec crate motor, no egr, no smog/cat, a 2800 stall TC, I get 24mpg highway. That's using a 180 stat. I ran a 160 stat for a while but it's not worth it. The motor needs to get up to 180 for it to do it's complete job. It won't hurt anything to keep it cooler, I just have found no power from it and infact the car drives a lot smoother with the 180 adn even 190 temps than it ever did at 160. It's amazing how much stuff I've tried in just these past 4 years

Hey Jon do you have a part # for this air cleaner? I haven't seen one that cheap.

I would reccomend unchoking your TBI before doing anything.
Of course, it wouldn't hurt to do the little things like ignition upgrade, fine tooth comb tune-up, etc.

My concern being money spent on upgrading the exhaust system can be stretched to make sure the whole car is in good tune, the tbi gets unchoked, adjustable fuel pressure reg, plugs/wires/cap&rotor. Get all the little annoyances out of the way. That way you can purchase bigger mods in the future without hesitation knowing full well you made sure the car was first ready to make the most use out of aforementioned "bigger mods".

Just my viewpoint. Good luck and happy tuning, bro.

SUM-G3000
It went up in price a hole 3 bucks. $17.95

thanks!

was there any more info on those members that would do the ultimate tbi mods via mail in?