oil pressure sending unit block and washers
 

When I took the mounting block off the engine that the oil pressure sending unit attaches too it had aluminum washers on both sides. I didn't have alum. washers and I didn't want to use the old ones so I used some new coppers ones I had for the oil line bolt on the side of the engine that were the same size. I couldn't torque the bolt (with the hole that goes through the block) accurately b/c the torque wrench wouldn't fit down in there so I had to do it by feel.

Low and behold I have very small leak b/t the block and the engine. So I tryed tightening it again with a 7 or 8 inch wrench. I found I could still tighten the bolt (with the hole) some more (say 10 - 15 degrees) with just a bit of force. I didn't want to keep pressing my luck and strip the threads so I stoped there.

My question is can you use copper washers for this or do you have to use aluminum?

either will work fine.

ok, good.

Do you have any recommendations on what kind of torque wrench to use to tighten the bolt, or is just snugging it up ok?