No such thing as a pressure reducer. There's oil being sent at full engine pressure to the gauge. You can get a later gauge that's a 0-30-60. Link I think some vendors have the individual gauge to put in your cluster.
Or you can see if your original works and doesn't go full scale. Doubtful if it will hurt the gauge unless it's REALLY high pressure being sent to it.

Individual 0-60 gauge Link

Last edited by klhansen; 01/13/2023 12:02 AM. Reason: added link
Kevin
1951 Chevy 3100 work truck
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1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.