fuel tank sending unit

Our fuel tank arrived for our build, we went with the 78 Chevette fuel tank. But finding a chevette fuel tank sending unit to fit is a rare as unicorn crap! Question. As I'm running a Ford 302 5.0 HO, can I use an 89 mustang fuel tank sending unit?

Not likely.  Ford and GM used sender of different resistance.  Your best bet is to use and aftermarket sender by someone like VDO.   VDO does list a sender that is GM resistance. Some were 0-90 ohms and others were 90-0 ohms.

You will need the steel mounting plate from a GM sender since it will fit in the hole that is already in your tank.  You could get this from just about any GM sender from the 70's or 80's.  The donor sender doesn't have to be functional, you just need the plate that it mounts on.  Get the seal and locking ring that seals it into the tank since you will need those parts also.

You could then adapt the VDO sender over to the GM plate.  The VDO sender mounts through a single small bolt hole and is adjustable for the depth of the tank.  It should be fairly easy to adapt.  I got lucky and was able to repair the non-working sender that was in my car.

If you have not bought your gauges yet, don't worry about getting the GM resistance.  Get the unit that is correct for whatever gauge you buy, but you will still need to adapt it to the GM tank.

So I purchased a replacement tank as well but ended up using the OEM sender/vent/pick up. My VDO fuel gauge is 0-90 ohm so the sending unit should be compatible to that assuming you have the standard issue gauge. I would measure the diameter of the tank opening, both the inner and outer lips, and call Summit. They, or doorman likely have a aftermarket part that would work. If the other part you mentioned fits the tank and can be locked down then you could take the sender, a battery and your fuel gauge, hook it all up out of the car and test the calibration.

On mine, the gauge remains on Full until about 100 miles, then does the bob and weave dance down to fill-er-up time. I am working on a new aluminum 16 gallon tank which is baffled and should stop the needle dancing. For that application I purchased a sending unit that permitted adaptability for different size capacity tanks, Hotrod turned me on to it.

I've found a sending unit for a mustang II which I think would fit into my 79 chevette fuel tank. The engine I'm running is a 89 302 EFI, so think it would be better to go with the ford mustang ii fuel tank sending unit no? Assuming diameters for fuel tank opening are correct.

Sorry, just checked original packing list. Looks like we have a VDO Fuel Gauge (Chev) so that answers that question....