First, I must tell you that your idea is a bad idea. The fuel gauge what is used on classic era Boston Whaler boats is a much better fuel level indicator than you can get with any remote electrical gauge. There are two significant advantages to the existing gauge:
- it works without any electrical current, and
- its dial pointer operates over a 270-degree arc.
The reasons these are advantages are:
- there is no effect on the tank level reading if the battery voltage changes, and
- the much greater arch of the current gauge compared to the much smaller arc of an electrically-operating gauge gives you better resolution in reading the fuel level.
If you MUST have an electrically-operated remote gauge, you can still retain a dial pointer magnetically linked gauge. For information see the article on RECOMMENDED SOURCES and VENDORS at:
https://continuouswave.com/whaler/refer ... #fuelGaugeFollow-up with the recommended vendor to get the needed replacement part.
Also, I doubt you can find a "drop-in" replacement for the portion of the fuel tank level sender that is actually in the fuel tank. The OEM fuel tank level sender uses an unusual four-bolt bolt pattern. Most of the "replacement" resistive fuel tank level senders do not use the same bolt pattern. This is another reason why your idea is not a good idea.
What you are proposing is to "fix" something that is not broken.