So I'm taking my carb apart and measuring things for a K&N air filter but I have a problem... The carb I have LOOKS like a HIF-style unit (flat-bottomed with throttle and choke levers predominantly on the side of the body, etc.) but when I measured the main air intake opening it's precise 1 3/8" and NOT the 1 1/4" or 1 3/4" offered in either of these two units: HIF6 (1 3/4" opening): HIF6 HIF44 REBUILT CARB INLET MANIFOLD W/LINKAGE 1 - Classic Mini Cooper HIF38/HIF4 (1 1/4" opening): 1 1/2 HIF38 HIF4 SU REBUILT CARB INC. MANIFOLD & F - Classic Mini Cooper So far I've tried three different units from K&N and NONE fit, and I'm starting to wonder if someone bolted a non-Mini carb onto my car when they converted it from SPI. Any ideas??? PS - this is the only identifying mark I can find on the unit - this is inside the top pot assembly: There's also a "06" (or maybe a "90") cast into the side of the main body.