Does anyone know where I could get a new rubber(gasket o-ring)that seals the filler neck into the gas tank. 1978 Ford Fairmont
Almost all Fox-bodied Compacts and Mustangs from 7'8 to '83 should work. No idea who makes any replacement tanks, but they'd likely have them.
I don't know about Ford, but for the GM cars you can still buy them from the dealer. I have bought several for different year GM cars from the local Chevy dealer. Importsmasher
In case you haven't solved that yet: http://www.transferflow.com/ford_fillneck_kits.html http://www.gastanks.com/ On this one, hit the eCatalogue menu (popup window). They make the tanks and seals for the second link (rads too): http://www.spectrapremium.com/spectra.html