?So just tap the hole to 1/8" npt? Will this leave enough material for the new threads? Also guess I'd have to use the die to put new threads on the sender to fit in the T/valve setup I intend to use.? ? It's not new threads. They are the same pitch. By running the tap a little further in it will enlarge the hole and let you screw the fitting (US pipe) further into the fitting. Or in reverse by using a die on a US pipe thread and running it further on it will reduce the fitting diameter (same thread and pitch) so that the fitting will turn into the metric fitting far enough to hold and seal. I have found that opening the metric fitting with a tap works best for me. You might put some grease on the tap to collect any metal shavings. Rodger Wrona Rollsdoc MT49PH