My experience with sending units these days is they're all of questionable quality. That includes what is sold by the european parts places. It's all that is available anymore. There have been issues with them being wired backwards (as documented in the cleanflametrap page), leaky float ***** (keep your original float ball just in case assuming it was a factory unit).

 

its the in-tank fuel pumps that are wired backwards. For sure, test the assembly before reinstalling.