Theres a guy on thirdgen.org with a stock heads/cam tbi in the 12s on nitrous... if I recall right, he goes 14.9 off the juice and 12.9 on it - 120 shot.

Regardless, on a stock LO3 the tbi isnt holding it back, a peanut cam and swirl port heads are, along with an excessivly restrictive exhaust. Once you start doing heads/cam then tbi becomes a problem, but if you're sticking with stuff like full exhaust and an intake manifold then there's no need to rip the tbi off and shove a carb on top of it.

 

EVERYTHING on that engine holds it back, including the TBI! You can put heads, cam, intake, exhaust, aftermarket TBI, proper ECM tuning, and all the driveline mods to support it. Many have tried to go fast with the mods above, and everyone that I've seen has failed. It will still be slow for the parts put into it. The TBI itself is a very poor design, and that's why no one uses for high performance use. 14s and maybe 13s on heads/cam 350 TBI is nice. But the same engine under a carb or MPFI system will be stronger.

Again, all you need to do is show me a TBI car, I don't care if it's got a BBC under it, running at least low 12s. Until then...

 

looking good for 250$ sweet deal

 

WOW! NICE deal for $250! Heck I paid $900 for my '84 Z28 with the 305 in about the same condition. Probably worse.