I, too, have replaced the cylinder head on the 617.

However, I would not recommend that you attempt this unless you are fairly knowledgeable with engines and especially familiar with the quirks of this engine. There are several critical steps along the way.......which if ignored.......or if screwed up.......will leave you with a pile of hardware that won't run.

It's also very critical to put all the small fasteners in suitable bags and label them as they come off the engine.......otherwise you have no hope of figuring out where they all go.

You need to have a lot of patience for this task. Every step must be planned to avoid costly mistakes.

The procurement of the FSM for the 617 is mandatory for such a task.