turpentyne,
Unless someone has information about a GMC oil filter set-up, you might want to also join the
oldGMCtrucks.com discussion group and post your question there. The GMC filter is on the distributor side of the engine (Chevrolet filters are usually on the manifold side) and the 1948 GMC temperature sender is (I think) electrical, while the Chevrolet sender is mechanical, but I am not certain of this (for 1948)
The oil filter in attached differently on GMC engines in comparison to Chevrolet engine. My GMC engine is about 20 miles away in cold storage, so I cannot get you specific information. Tonight, I'll try to remember to check the GMC Maintenance Manual to see if there is a photo or a description of the oil filter set up.
Maybe someone will provide information for a GMC engine.
Tim
