What is the approximate going cost for a timing chain professional replacement? Friend of mine is doing it as a favor and I do him favors. I'd just like to know cost so I make sure we keep things even.

He's the most competent 617 guy I've ever met, ran a machine shop for decades, etc. so he will be doing it right. He's also going to zip the timing up a touch and check all injectors. It's the "snail" that my deceased little brother drove, so I have to keep it forever.