I own at 1980 SD1 3500. The car was originally EFi but the guy who owned it before me took all the equipment off and changed it to carb. It currently has a 4bbl carb on it and I now need a new gas tank because the old one is shot (it sat for 9 years before I got it) and a new sending unit. I was looking on Rimmer Bros and they have both EFi and carb model tanks which one should I use? and are the sending units the same, as in will they work fine with my gauge? or do I need to get the EFi or carb sending unit based on which tank I get?