You need a drill 29/64 or 15/32 ,, a 1/4"-13 NPT tap, this will give you a 1/4 pipe thdin to the manifold .
first i found and marked a spot on the manifold where i wanted the fitting, removed the manifold, drilled tapped washed with hot water and soap. screwed the 1/4 X 1/8 fitting into the mainfold got it snug + 1/2 turn looked inside seen how much was sticking into the manifold,,marked it removed the 1/4 fitting cut off about 4 thds reinstalled and tighten it was just past flush inside the manifold, reinstall the manifold,, connect the 1/8 fitting that came with the gauge and tested it. will put gauge in cabin soon ,, it is very simple to do. ,,
good luck jim
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