I went through this many posts ago but I'll do it again just because I'd hate to see someone waste time and money. There was absolutely NO performance gain shown on three dyno pulls with the addition of the BBK Cobra throttle body to the stock (ie naturally aspirated) Bullitt. If you want to do it anyway, here's what you can expect even with port matching, and yes you will have to do it, you will find that no matter what the butterflies just don't seem to seal right. The linkage did not work with the stock Bullitt linkage which in turn caused severe idle problems. For instance, at idle we only managed to settle the rpms down to about 1000. However, after a throttle up the platewould remail open on the throttle body and cause the idle to hang at 3000 rpm. I put the stock throttle body on and everything returned to normal. When I returned the throttle body to Brothers they said that they had several returns already for driveability issues as well. This occured in June the 18th to be exact so maybe BBK has a specific Bullitt application I'd suggest just giving them a call and speaking to one of their tech guys. I did that initially and was told that it may or may not work but since they hadn't tested the Bullitt with the current product inventory. In any case, unless you plan to add forced induction the current throttle body is more than adequate for all of your natually aspirated needs. The real congestion in the system is the manifold/ H-pipe. Further gains are being tested as we speak by Paul Svinicki. Though he hasn't said specifically I suspect that it involves some intake work much like the stage to Cobra intake that he currently sells. Anyway that's my two pennies.
Arthur
