I have 3 oil pressure gauges.
333722-R91 came with the '49 when I got it. It has no numbers, just an indication for IDLE and RUN. The glass is cracked on that one, and it always seemed to go to the IDLE after running up to temp. I took that one off and replaced it with 364665-R92, that one came off my '67 Loboy. It has numbers 0 to 75. This one would also go to what I considered low pressure @ 15lbs. when up to temp.
When I was visiting with Rudi this summer he gave me another gauge. The 31041-08 (looks exactly like the one I had on the '44 A) This one has no numbers, but has a "RED" zone at the lower end. I installed it last week and so far after running under good power pushing snow for an hour or so, it indicates less than half, but nowhere near the red zone. I'm feeling good about that.
Are any of these gauges proper for the '49?
She's running real sweet, no smoke, except white when it's 25 to 30 below. I'm running 10W-30.