Hi just started it up the first this year when itso when it was warming up I smell oil it is on a 81 Ford e 350 with 460 how hard it to replace the valve gasket s
Also, check the valve covers to make sure they are flat, if not lay it on the flat edge of a table and hammer it flat. That is a cause of leaks at times.
Check to see if all the valve cover bolts are tight. I had an 85 that both valve covers leaked when I got it. After finding all the cover bolts loose and tightening them, no more leaks.