My question is basically this:
I need some advice on what exactly i should do before i slap on some cold air intake and custom exhaust system - i am 18 years old and my daily driver is my only car (1991 firebird with a 3.1 MFI) - its slow, and has high miles (87,000). What kind of tune ups, preperation should I be looking into to prepare my poor old engine for the modifications?

Im looking to Add cold air intake, 1.6 roller rockers, hi perf pulleys, dynomax exhaust with ultra flo muffler and a hi flow cat converter.

I know the most sensical thing would be to get my engine and tranny rebuilt, but keep in mind im a broke college boy and need a more economical solution. any help is greatly appreciated.

 

OK First lets clear up a misunderstanding. 87000 miles is NOTHING for a thirdgen. That's practically LOW miles not high. Mine's got 165000 and there are plenty of people on here with over 200000.

Anyway, I would not recommend rebuilding the engine ever. Brand new 350s are so cheap you can just about get one for the price of a rebuild. Your only problem would be if your state has limitations on engine swaps (even then, it's supposedly OK to swap to a different engine option offered by the dealer in your model year). And of course a V6-V8 swap is a hell of a lot of work when you're new to working on your car.

So let's go back to your other questions... Most mods are not really "hard" on your engine... The only things that you should watch out for would be nitrous, turbos, blowers. But a cold air intake or high-flow exhaust, etc will in no way hurt on your engine. So prep is really nothing. Other than the standard take good care of it (change oil, plugs, wires, etc). But you should do that even with no mods.

The cold air intake is probably the easiest thing to do first, if you have something in mind. Sometimes routing an intake hose is a PITA, but it should be easier with only a V6 in the engine bay.

Assuming the rocker arms are the same as on the V8s, those are no big deal, just be careful to remember where all the bolts came from when you pull the valve covers and anything else in the way. Pulleys too, just remember the belt routing.

Exhaust is the hardest, since you'll be cutting off the old exhaust (easiest way to remove the I-pipe where it goes over the axle is just to cut it and pull one piece out the front and one out the back), and exhaust work sucks. Lots of old rusty hangers, it's hard to get clamps tight enough to seal, or you have to take it somewhere and pay someone to weld it for you (you can weld yourself, but the muffler's awful close to the gas tank... I'd rather pay $60 than get myself blown up). The cat is a pain too since if you're not putting on headers, you have to CAREFULLY cut through the old Y-pipe where it slips over the cat in order to get the cat out. But you don't want to cut the old Y-pipe too much since you don't want to have trouble attaching the new cat.

If you think it would ever be on the horizon to do an engine swap, I would focus money on things that will apply to the new engine as well. So get the exhaust before the rocker arms, since the rocker arms might not transfer to the new engine. Things like that.

Oh I almost forgot. One of the best mods is gears. Find out what gear ratio you have now. If it's the lousy 2.73s, consider a swap to a better ratio like 3.23. GEAR swaps are very difficult and touch things, however WHOLE REAR AXLE swaps are far easier (just heavy). And frequently you can find a whole axle for $50-$100. Sometimes getting brakes hooked up is harder, but if you have drums now and get a rear with drums it'll be pretty easy. Of course getting one with discs is a nice upgrade but then there is some hassle and $$$ involved in hooking up the discs instead of the drums. Going too high on the gear ratio can hurt your gas mileage though.

 

I think one of your best bets would be to make the car as light as possible.