I used an off the shelf, universal fit, Tempco unit from West Marine.
It was a major pain to install and is not very accurate.
I wish I had know about this other company.
Might even consider chucking the current one and going this way.
the accuracy of any fuel sender has to be adjusted by the user during the install process.. even the wema type...
so if you dont take the time to do that during install, you will not be happy with any of them. if the sender is actually faulty, then it can be returned for replacement, but an error in installation cant be counted against an otherwise excellent unit...
for the tempco unit, the bracket length needs to be adjusted so the pivot will be about halfway between the top and bottom of the tank.....
then the float rod need to be adjusted for length so when the tank is full, the float almost touches the top of the tank... and when the tank is empty, the float touches the bottom of the tank.... this puts the sender in "time" with the tank depth/volume.
sometimes if the bracket length is not perfect, the float rod may need to be bent slightly to get the float perfectly centered between top and bottom of the tank....
if you dont adjust the bracket length to somewhere close to where it needs to be, and/or... if you use the float rod full length, the float will either hit the top or the bottom of the tank BEFORE the sender mechanisim reaches full stroke to read correctly...