I'm very sorry but I was mistaken in regards the spark plug type. I was confusing my 26GT plug (which is an NGK CM6) with the one in the 45 IRS which actually have a Champion RDJ6J. I cross referenced the RDJ6J and it shows that the NGK BPMR7A is the direct replacement alternative. I noticed your catalog shows the NGK BMR6F 14mm taper seat spark plug (16mm Hex) as the closest match available. My question is; If I purchase the Vlach ignition upgrade, will the booth in this ICU fit either of these plugs without the need of replacing the booth cap?