Do I have to pull my tanks to replace the sending units and gaskets or can I remove without pulling?

depends how much room you have and the style.  if its a typical "floater" sending unit they can be quite interesting to fandangle into the hole.

Forgot to say its a 74 Sanger super jet with saddle tanks

Capacitive technology has no moving parts

Excellent long-term relibility in extreme environments

-40°C to +125°C operation

0-5V Analogue Output compatible with most systems

Very lightweight - from just 25g

Get a stick stop every now and then dip the stick and see how much you have lol

All jet boats are this way, aren't they?
Notches on the ski flag.

Daniel