Hello. I'm looking at ordering a new larger throttle body and plenum for my 2004 GT. It has the stock 4.6L V8, and the only mods I currently have for the car are exhaust (Pypes off-road H pipe, M80 mufflers), and a Cold Air intake. I've been looking at the BBK assemblies that incorporate both the throttle body, and plenum into one unit. I see they offer it in two different sizes (73mm, and 78mm). Everyone thinks the old saying "bigger is better", but I've seen reports of the 78mm unit actually hurting performance on lightly modified motors. After finding that out I think maybe the 73mm model might be a better choice. I don't plan on adding forced induction to this motor (that's where a 78mm TB would shine). I can get the 73mm (Part #17801) brand new in box for around $200 from an online supplier I found. Worth it? Or can HP be found else where with that same money?