ill go up in prop size, i have an 11x10 apc to try...The pipe im using is a macs muffled pipe if im not mistaken, its close to 19 inches long... im gonna have to order a macs long header for the OS 61, ............ for those of you that have tuned them.....How much would i need to cut off from a brand new macs header,to be in the optimum range?>



Ill try an 11x10apc during my lunch break tomorrow, its getting too dark to get any good tach readings