Well as Kieron pointed out the Filter is the easy thing to change,and would be the first thing on the list.
Where do you live Thomas? cause if it is a hot climate the 15W-40 might be a little thin in a hotter climate.
Used to be Mustang1966coupe.
66 Silver Frost Mustang 289 Windsor
71 XY GS Fairmont in Bronze Wine 302 Windsor
92 EB XR8 302 Windsor
Sure do love those Windsors