The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post

kipps · 10-05-2019, 04:45 PM

The fuel sending units are not interchangeable, or at least aren't intended to be. When installed into older carbureted tanks with no baffles, they might be interchangeable. In a TBI tank, the sending unit won't set in the basket correctly. Also, the external lines are longer on the passenger side, for some reason.

GM called one tank the primary, and the other tank the auxiliary. To confuse things, it appears that GM changed which tank was the designated primary in the late 70's.

Regardless, if you order one of each sending unit, you should have a set.

10-05-2019, 04:45 PM	#2
kipps Registered User Join Date: Jul 2014 Location: North-central Virginia Posts: 1,099	Re: Tank sending units The fuel sending units are not interchangeable, or at least aren't intended to be. When installed into older carbureted tanks with no baffles, they might be interchangeable. In a TBI tank, the sending unit won't set in the basket correctly. Also, the external lines are longer on the passenger side, for some reason. GM called one tank the primary, and the other tank the auxiliary. To confuse things, it appears that GM changed which tank was the designated primary in the late 70's. Regardless, if you order one of each sending unit, you should have a set. __________________ 1987 C6P V20 truck, 2010 LMG 5.3, AFM delete, 2010 Camaro exhaust manifolds, 1997 nv4500, 1991 np241c, hydroboost, 2005 14bff axle & driveshaft, drop-n-lock gooseneck, 4.10 gears, stock suspension, rims, and tires. Still a work in progress. Any questions or suggestions are welcome!