I would get the updates and do basic maintainence. New airfilter (maybe at this time get a AFE, BMC, MS or other replacement filter). I mean my baseline dyno for my 2011 M3 was 345rwhp and almost 260 tq. This was the mid base numbers from the 3 runs..Car only had 1500 miles on her, but it did have 93 octane.
To be off by almost 40rwhp is a ton, unless the dyno operator did something wrong.
BTW, the day of this dyno they strapped down a brand new 2011 Mustang GT 5.0 and it did 366rwhp/350tq...I felt small and puny..
Dave