BigRigTech
Diesel junky
Some do pass through into the block.
I drilled the trans case last night....I had to open the 2 top holes up to 1/2",then I bolted on the spare adapter using the top two holes and drilled through the adapter for a guide....Everything went ok from what I could see.....The dowel holes are 3/8"....I just have to to do the same to my tin spacer plate as well.