I'm not going to cast too many aspersions on the heater box. At the time it was removed, someone thought "well, we have plenty of time to worry about that thing" and when we put it on, we thought, "let's get this on here so we can hear this engine run". No one thought about it in the intermediate term. It wasn't a safety of flight item, and would've been fine until the next annual, but it just seemed to me that there was no better time than now to get a new one. I had told the guys that i wanted to keep the cost down as much as possible this year (lol), so it's possible it was looked at and not deemed bad enough to condemn yet. The mufflers are only a year old, so the exhaust system should be sorted for a few years. I'll be much happier if I never hear that rattling noise again, particularly coming from an engine that I just put together...