Using a 1/2" drill body and a high quality hole saw I cut the hole in the fuel tank. Then laying out the plate I marked and drilled the bolt holes. Cleaned up all the shavings and installed the port. I did coat all the bolts with a Zinc Chromate product and then bolted it together and snugged the bolts up similar to how one would on the lug nuts on a automobile.
After 5 years of cruising I opened up one of my tanks, removed the Seabuilt Port and reinstalled it. It truly is a joy working with a companie's product that behaves exactly as they say and lasts like it should. Thank you Seabuilt!
Would I buy these again. You betchya! Grade A!