Spectre sells a 4" aluminum tube (about 6" long) with the bung welded on for a blade-style. It's about $30. I'd give you a direct link but their web site is absolutely lame. Go here:
http://www.spectreperformance.com. Look in their catalog under "Modular Air Intakes", "Mass Air Flow Sensor Solutions" and "4" Polished Aluminum MAF tube".
Gregg