Blower overdrive increase vs tuneup

Hey guys I’ve got a healthy 540 bbc w/an older but fresh Littlefield 1471 hi helix on methanol, wanting to increase my overdrive from 42% to 46%, how much would this lean the motor out? Is there a rule of thumb for overdrive increase vs pill size change? An uneducated guess would tell me to richen it up .005 but I’m still pretty new to this, thanks

 

.005 or .006 seems pretty close for an average setup. On my 8mm stuff .004 per tooth works well in small windows. For big swings I usually go back to the calculator. I would never take an on kill tuneup and make moves like that, but if you're burning half a thread and not hurting bearings I think you'll be ok.

 

Big difference between a .065 jet to a .060 and .130 jet to a .125