Ive got Kevins dune/play port job and it rips.Very smooth power band.I have a set of 33pwks,timimg set at +4,shearer pipes,+4 swing arm,cool head with 19 domes running avgas...but like the previous member mentioned,I should have done a 4mil...like Kevin said to me "you will the fastest in your camp(all have 450's) but will get beat by anoher bike in the dunes"..thats when you willl wish you did the 4mil...