I"m trying to hook up my oil pressure guage, and there are taps on the head for this, there pluged with allen screws. The fitting I had didn't work, I need to know the correct fitting so I can finish the install.

Thanks

 

I would tap it by the oil filter area.

 

my guess would be 10mm x 1.25 pitch, if not 10, 8mm. almost everything on the evo is that size

 

He's talking about the oil galley plugs, they're not a normal bolt. They're a tapered pipe thread plug, but it's not NPT, they might be BSP.

You don't want to go off the head for your oil pressure gauge, you need to go off the filter housing. The head has a pressure restrictor on it so your readings won't be accurate.

 

really?? I heard people tap this and guage works fine?? I Dont really want to tap at the filter, I guess I could run a line up to the sender, that sender is jsut heavy and I dont want it hanging off the block.

How off would the readings be?