I was speaking yesterday with a mechanic and he told me that if you want to use throtlle bodies into your car and you wand a good performance you must use and uprated cams into the c20xe engine.
Because with throttle bodies we have more ail and more fuel and more avans(I don't if that is calling in english), and usually the fuel mixture is more reach.
With all that throttle bodies are designed to work better in high rpms. These is the reason that throttled bodies is better to work with high performance cams. I think that the standard camshafts is working well up to 6300 rpm.
they run just fine on standard cams - for a standard engine, the cams are actually fairly aggressive - sure throttle bodies really come into their own above 6000rpm - where performance with the standard cams are beginning to fall off - but nevertheless, you're still looking at 190bhp on a well setup engine.