I just ripped down the original 305 TBI engine that was originally in my wife's 92 Camaro RS. Like all TBI engines it has the lousy "swirl port" heads where the intake port behind the valve is about 1/2 of the way blocked off by a swirl vane built into the casting. Good for swirl, horrible for flow. I could probably take some (bad) digital pics of it if anyone cares to see one of the reasons why stock TBI engines are so difficult to get real power out of.

 

http://customclassictrucks.com/techa.../0405cct_head/
They have some awesome pictures of how bad swirl port heads really are.

 

Yeah, that's them. Picture right at the top of the page in that link.