I am certainly familiar with 617 oil leaks.

On the left side of the engine the principal culprits:

1) Oil cooler line hoses. If these are wet where the hard line meets the hose, they are leaking. The entire underside of the SD, beneath the driver, was wet from long standing cooler line leaks.

2) The oil filter housing gasket. Over time, this gasket dries out and leaks.

3) The IP gasket. It takes a beating every time the IP is adjusted and it's a cheap paper gasket. PITA to change because you have to remove the IP to do it.

The leaks on the right side include the intake/exhaust manifold gasket and both the drain tubes.

The valve cover gasket should not be overlooked.