Oil pressure slow to rise

Check the level of oil with engine off and after it sits for a hour.

Suggest checking/topping up the gas as they will not kick in on low pressure.Otherwise you can get back to me.

I would check the coolant temp sensor.

It should be pretty close to your oil filter.

No not the fuel pump. You most likely need to do a tune uo. New spark plugs, wires, fuel filter, air filter. Deffinently change out the spark plugs. I would suggest using autocraft, autolite (fords brand} or some densos or ngk for better performance. Hope this solves your problem.

first is this a electric gauge or manual??what weight oil r u using? i would suggest 20w 50 also if it was me i wold pull both motor and trans in one piece easier than doing this on ur back. sounds like the oil pump is going out or the pu screen is half pluged

You oil pressure sending unit has gone bad, it's common to go bad and some even leak oil. 
The oil pressure sensor is on the back of the block on the passenger side, you can get to it from the top and not from the bottom. There are (2) switches back there that screw in to the block and you can only see it from the top of the engine. The Oil Pressure Sending Unit is the one wire harness with a green and white strip on it. The other switch has more wires to it. 
When you pick up the new sensor, make sure you get the right one. make sure you get the Oil Pressure Sending Unit which sends variable oil pressure and has only one quick connect for the wire connector. The oil pressure switch is the one that only activates the oil light on older engine. 
Once you get the right part at Auto Zone for around $9.00, disconnect the wire clip with the green with white strip on it. and use a deep spark plug socket with a extension and u joint to get the sensor out. The sensor comes with teflon tape already and no oil should leak out from the block. It as simple as replacing a bolt and reconnecting the wire connector. 
Good luck and hope this helps, take no more then 10 min to do but about 5 hours for the engine to cool off LOL

Replace your oil pressure sending unit. Usually costs about $10.

is the engine rattling? during this time?
if not you have a bad sending unit!!!