I do. My understanding (based on info from Sean and Chuck T.) is that there's no effective difference in overall HP (that charges as you add significantly more modifications). There IS a difference in the sensitivity of your accelerator, so I guess you could project that with the larger TB's you might have greater HP a bit quicker.
It seems as tho you and I are in the same boat. We both asked the same questions about mods... /images/graemlins/laughing.gif The TBs will not show any noticable rwhp gain with the Roe S/C. My friend who is doing my S/C has them in his and he said that they show no gain at all (Sean said that as well). Also, when you get into TBs, you need to take into consideration the heads and CFM (Torquemonster can answer this better than I can). But from what I have found out, it is a waste of money unless you are putting new heads, etc... That is why I had a thread about who makes the best heads. I am considering new heads for my car. BTW, how fast are you planning on going? Should you be running the 8psi pullies, you should be set.
Also, another consideration is to ask Snakebitten about his NOS set-up in his car. Those are my two choices, heads or NOS. I am swaying towards NOS (more hp per dollar). So instead of spending about $500-$600 for the TBs, go get yourself a 100-150 shot of NOS... :cheers: