That's odd. I have been running FLM bulks since my E-Maxx was new. And I got the extended chassis about a month or 2 ago. They went together like butter and work great. I really like the chassis.
I am pretty tough on my truck and this stuff has taken it all. Anyone who knows me can testify to how I run my truck. I would recommend FLM to anyone who asked me.
Anyway, good luck with your parts. Post some pics of the finished pieces.