Just break it in according to the manual, then enjoy one of the easiest motors there is to tune! I think you will get better performance with the 8mm restrictor in a truck but run times will suffer some especially with the JP-1, no secret that they are fuel hogs. But the engine will run extremely well with it! Just keep an eye on how easy the needles turn, I havent had much trouble with the lsn, but have seen the hsn start turning real easy. If it starts turning with little effort replace the o-ring. My engine is one of the earlier ones and I'm pretty sure a different o-ring is used now, but just more of a preventative maintenance thing than anything (I have seen the hsn spin in the housing while the engine was running). This thread is full of good info on this mill, plus the customer service is excellent! So enjoy your purchase!