I have a 2005 MC with 115,000 mile on it with a 3400 and it just started to knock. from what O can hear it sound like its coming from the bottom end so Im guessing it might be a crank bearing. No the big question how hard, what would I need and would it even be worth it to swap to a 3800 N/A. Or does some one have a 3400 engine they would like to get rid of for a desint preice? I live in Woodridge, IL so the closer the better.