Cab. I don't know what plugs came with the engine, non running when I got it and they disappeared during rebuild. Been chasing an ongoing issue with the engine and a buddy suggested that I'm running the wrong plugs. Last night I finally found some info on a motorhome web board where they stated they are using Champion BL9Y or RV12YC. I am currently running NGK UR4-V power. So next step is to see if these plugs show to be interchangeable.
I was just wonder if anyone on here had the same motor and what the were running to give me a starting point for compatible plugs.
As far as my engine it's bored .30 over with stock pistons, only upgrades are a mild D/C cam, Weiand intake, and headers.

My Dad always told me, when setting goals " avoid disappointment, aim low".