I made the mold for the oil dipstick access out of a plastic cup and a baby food container that I covered with electrical tape and petroleum jelly for release. I marked the location and measured how deep and how big I should make the hole at the bottom of the part to allow insertion and removal without losing too much air. Also, how big a hole on the plenum chamber. After some minor ajustments to the holes I inserted the part in place and used hot glue on the outside to fix it. I made a transition with flox and let it cure overnight. I finally grinded the excess on the outside of the chamber to make a transition on the edges.

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