What is the filter # and what oil do i use?

What is the filter # and what oil do i use?
Added (1). I have a 1988 Ford motorhome Econoline 350 ( 7.5? ) How many quarts of oil do i buy and what is a good filter. I hear a ticking and want to change the oil and filter. Should i use mobil 1 oil and what filter if i use synthetic do i need a special filter? 5-20? 10-30? Oil. The filter currently in it is carquest R-85515.

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