Some '91 Firebirds came equipped with a tuned-port injection system, in which each cylinder got its own injector, and thus, a more precise mixture of petrol and air. This meant better fuel economy and more horsepower and torque.

Throttle-body injection, though, was much cheaper to manufacture, more reliable, and easier to fix if there was a problem. In this design, there were two injectors which each provided fuel for one bank of the V-engine.

Because of it's simpler design, though -- actually rather similar to a carburetor -- throttle-body injection has a lot of options in terms of performance-enhancing modifications (some of which are more difficult to do with a tuned-port system).

Two rather simple things I'd like to do to this car this fall and winter or maybe next spring are a) add a cold-air intake or otherwise improve air intake and b) change the rear axle ratio for a little extra zip. I'm not sure if I want to go through with the second, actually -- this car guzzles gas as is.

I'm hoping that by next summer I can find a 5.7L or an LT1 that I can drop into this thing. The 5.7L would be easier to install and probably a bit less expensive, but it would just guzzle gas all the faster. An LT1, on the other hand, would probably offer better fuel economy than the 305 does, but I believe it requires a conversion kit to install because of some design differences, and it would likely cost more, too.