Confused what to do with a 5.9L serpentine setup

FYI: I have an idler for the Magnum if you need one.
Thank you for the offer. I actually just pulled it out of the old parts pile from the tear down from the magnum. My tool and die buddy stopped by last night and we have a pretty good plan. He’s going to machine a 1” template off the hole spacing on the iron magnum heads to use to layout and drill the holes into the LA heads so everything bolts up correctly. I’ll keep everyone updated with the progress.