if you aren't going to have gauges to keep an eye on things, I would let inmotion know of your change, and send it off...you can check with Rob, but this is the reason I am not driving mine hard with 240's manis...just don't know until I get the Zeitronic dashdaq installed to do some logging in order to get the best tune possible...when you are revving that high, for what seems to be a long time, it could be lean, or it might not, but I personally would want to know....but they make a big accelleration difference don't they...