From reading multiple threads on the 74mm upgrade.. The ID is the only difference. "Toying" with the idea of one myself, but not going with tune and everything else most do. Let me know if just the throttle body itself is a noticeable difference. I had read a thread where this alone doesn't make much of a difference .

Edit: Never mind.. just read your "splurge".. LOL .. Now break out the dremel and get serious about getting everything you can from it.. butterfly shaft grinding and edges..