i got the fmf powerbomb and the q4 put on my 2011 310 last weekend. Everything lined up perfectly. It is closer to the radiator hose so i wrapped it with exhaust wrap.
I just got my 2010 Te250 xlite and I purchased a Sealey 16mm thin wall sparkplug socket part # AK6557. OD is approx. .785'' and fits with significant clearance. This part is listed on ebay frequently. Below are picks of the socket, OD and setup that fits to change the plug without removal of any other parts (kinda of a Frankenstein setup but it works!). Hope this helps any others looking for the right tool to change xlite spark plug. cheers!