I bought a 6.4L intake for my 6.1 w/6.1 heads and the intake hits the block right behind the timing cover (boss where the coolant temp sensor screws in). It does not appear I can massage the intake or the block for clearance. Is the intake face taller on the Apache heads vs. the 6.1?
Looks like I would need a 3/8 - 1/2” spacer to eliminate the interference. I thought that I had seen some spacers on here somewhere but I cannot find any reference to them now. Anyone have any ideas?

A spacer would screw up airflow, can you post a pic of the interfearance area?

here you go, it's hard to tell in the image, but the part that hits is a runner. If it was a strengthening rib, I'd trim it down...

the later VVT engines have significantly more room there. It looks like you could just carefully grind the back side of that water passage more flat, maybe trim off about .050 as at least looking at my parts pile it should clear or maybe just barely touch. I think you can make it work as it may just be a tiny bit of core shift in the block or intake or both keeping it from clearing. Maybe you could grind out the bolt holes a tiny bit to shift the intake back also then touch up the ports so they still line up. A little here and there should be enough unless you got a worse problem than I am seeing in your pic and my parts.

There was a guy in Canadia that ground and heat formed one to clear fine.