What happens if you install timing guides wrong? (4.6 2V)
 

Asking for a friend...

He switched the sides of the timing tensioner guides when putting in a new timing set on a Romeo 4.6. He said that they both fit in the same way, only one had a step/spacer on the pivot, and it did not contact with anything on the block or timing cover.

I checked on some old parts I had laying around my shop, and even on a core engine I've got, and I don't see how switching the tensioner guides could cause a problem, because they are free-floating, and not bolted down, and don't contact any part of the block or timing cover.
In fact, the original guides from the 5.4 I used were a universal kind with no step at all.
Why did Ford use two different tensioner guides, and will this cause a problem for me, um, I mean my friend?

The engine is still on a stand, so it won't be too much trouble to change it, but it would sure suck to have to take it apart again if it really wasn't necessary.

Does anyone have any input?

I've never tried mixing them around. The step rests against the block if I recall correctly. Are you sure you got them on backwards? If so, I'd definitely swap them around. If not, I'd still open it back up and double-check.