I ordered a block heater for the motor I am building. After some trials and tribulations I got the thread in plug out of the block last night and felt like the butt of a joke when after all that the heater was a different size. Looking around i see it should have an adapter with the kit, well it didn't. Does anyone know where to get this adapter or know the two thread sizes to where I could maybe look it up on McMastercarr or something? I would consider drilling and tapping the original plug but i'm sure it would be a challenge finding that size tap.