useing 25% to 45% nitro

[rick sterling]

hi if i run 25% or 45% nitro,will i have to put a extra shim on the
head,i have a ops 40. or no shim at all or just leave it alone,,thanks
for any help


--
rick sterling
------------------------------------------------------------------------
rick sterling's Profile: http://www.modelpowerboat.com/forum/member.php?userid=7110
View this thread: http://www.modelpowerboat.com/forum/showthread.php?t=1109
Free RC Model Boat Plans: http:\/\/www.modelpowerboat.com\/forum\/downloads.htm