i have an 89 firebird w/ a 305 tbi.

i'm gonna rip it apart, put in new piston rings, new gaskets everything, etc....

i figured while its apart i might as well see if i can get a good performance cam for it.

does anyone have any recommendations of one? maybe a site to goto?

 

Check out Comp Cams, Lunati (at Holley's site), etc.

If you want to get it to run better, start out with a complete exhaust all the way from the heads to the street. I'd suggest a chassis-specific replacement exhaust system including headers, [b]for some other car besides TBI[b]; get the one for something like a 88 350 TPI. That would be headers, cat, & cat-back.

Your heads suck as anything dimly resembling performance usage. They have these big "swirl port" ramps cast into the intake ports, that promote low-RPM driveability at the expense of flow above 3000 RPM or so. Get a set of 305 TPI heads from 87 up, they'll be casting number 081; those don't have the "swirl" vanes impeding the flow.

Your car desperately needs gears. Anything you do that increases the engine's RPM range will be a waste if the engine is pinned in the idle-2500 range by the grocery-cart gears those cars come with. Get a set of 3.42 or 3.73 gears, and a posi. The $99 posi from SLP (if they're still selling it) is the way to go.

Just sticking some bigger cam in an otherwise stock vehicle doesn't usually give the results one would wish for. Sometimes you can actually slow a car down by doing that; the kind of car you have is a prime candidate for having that happen, from over-camming it.

 

dont go crazy with a cam if your going to continue to use the SD tbi system. Id stay at or below 210 degrees of duration at the intake and probably, at the very least, an LSA of 112. 114 would be ideal. The tbi system needs a real steady (more like rock solid) vacuum signal or it will run like ****/not run at all with the stock prom. Even then it will still need tuning to run right. If youre really knowlegable at ecm tuning you could probably go higher but youll see rapidly diminishing returns since the tbi system is so restrictive. In carb terms, the best you can get is ~500 cfm @ 1.5 inHg out of one of the 454 tbi's. As i found out, getting one of the larger tbis makes a huge difference. Holley makes a tbi with 2 in bores but its not a direct swap at all. Try to get the 454 tbi from a HD pickup and some 65 pph injectors. Your engine will really apreciate the increased airflow. The stock tbi with the 45 pph injectors just wont cut it, period. Some people have run this and completly wasted their engine because it ran so lean.