Oil Capacity in 1990 SHO

I am doing an oil change for my buddy tomorrow and I need to know how much oil to use. He drives a 1990 SHO, what is the oil capacity with filter change?

Thanks

Does he have an owner's manual for the car? If so, it should be listed in the "Capacities" section towards the rear. On my '93 SHO, the capacity was 4.5 qts with a filter change.

-Rod