A two port will fit however it won't really be effective and may actually cause issues as it will restrict the engine breathing.
As Simon Says, Fit a 3 port minimum port 1 for the Crank case (15mm) and port 2 for the heads (tee'd together) port 3 return to inlet (ideally vta). Personally I'd go 4 a 4 port so the heads aren't tee'd and the final port vta's best I've seen is the one on Simbas car as supplied by Brent at SMD which has 3 inlet ports and a huge VTA port/filter so no restrictions on breathing.
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2005 Spec B 6MT - KiDO tuned (~270Bhp)
Custom exhaust - Cosworth filter - Samco Intake - Tints - Bilstein B8/B6 & STI springs - SuperPro ALK - Whiteline positive shift kit, rack mounts, rear adjustable camber bushes, front ARB mounts & strut brace, 20mm rear ARB with AVO mounts, - Hardrace Gearbox and pitch mounts - Prodrive PFF7's - Front Brembos - Kenwood CarPlay - 1/2 carbon grille - STI front splitter