New to me truck. Need oil reccomendation

[Triple_Se7en]

I would do a 3-4K OCI next - then monitor the results.

 

[DuckRyder]

I've run 5/30 and 5/20 in mine, it makes no appreciable difference in anything... It currently has 5/30 EPHM Mobil 1 in it.

I usually run Mobil 1 and a Fram Ultra for 2 OCI or a Motorcraft for one.

Get under it and check the timing cover near where water passes through form the WP, they are notorious for leaking there...

The already mentioned cam synchronizer, the PCV elbow (there is an updated one) and the heater hose assembly ought to be on your inspection list too...

 

[Silver]

Check that coolant for rust and alligators.