Robert,
If there is a "correct" way to install the oil pressure sender, you're supposed to use a restrictor fitting on the engine, a firesleeved hose to a firewall mounted sensor. Oil pressure senders can leak, so using a restrictor fitting is key. Better to have a drip instead of a huge leak. Mounting the sender away from engine vibration will significantly increase its lifespan.
I have a JPI EDM 900 engine monitor and the instructions specifically say "DO NOT MOUNT SENSOR DIRECTLY TO ENGINE" but there's no mention of a restrictor fitting. They specify an Adel clamp around the sensor attached to the firewall.
Vans sells a 45 degree steel elbow restrictor fitting for about $20. Wicks has an inline brass restrictor fitting for about $6. I think a restrictor fitting is a good idea on the fuel pressure sender hose fitting too.
Mike