Brian,

All the scoop you got was correct. I don't know what year GM sending unit would fit best, but if all else fails, Stewart-Warner has universal units in 90 ohms....I think!

EDIT. More research indicates the 90 ohm sender was used in '65 and later, so it might take a hands on check with a meter to be 100% positive. I have enclosed a interesting link on sending units.

http://yogisinc.com/results.cfm?Category=376


Stuart