FWIW the stock oil press gauge gives similar readings compared to my Mechanical gauge in my Laguna. The pressure will drop at idle more so when the engine is hot. A reading of "A" or the second tick is approx 30 psi, the first tick is approx 10 psi which is below the "L" Stock gauges are reportedly notorius for being slow esp tachs. My 0.02 any two gagues will not read the same anyways.
For the other stuff, It sounds to me that your clutch cable and clutch is worn. I got my 90 with 99K and the second clutch was glazed up and the flywheel was blued up and had high and low spots, the cable was pretty stretched out too. In goes a FMS iron flywheel, FMS A-302 clutch and a new throwout and pilot bearing. Get the Summit stock clutch fork kit with the cable for $45 since the fork was the only thing I did not replace and it was a little beat up. My clutch setup works awesome and smooth, perhaps on the stiff side, the King Cobra is easier but not as strong, and more expensive.
Get the trans rebuilt before it blows apart, it won't cost as much if nothing is totally broken yet.
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Frank W
90 5.0 LX coupe Daily driver. Silencer removed, K&N filter. Flexalite fan, 3 core radiator. FMS flywheel and Clutch, FMS blue wires Energy Suspension end links
88 Notch 2.3L 5 speed Parts/beater car
My two Notchbacks
74 Chevy Laguna Type S-3 305 Finally fixed getting a 454 to put in garage
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