Somebody posted an article and pictures of how to do porting mods to the nitro engine. Would like to thank that person. I know there was some negativity to him encouraging people do do this and screw up their already good runing mill. But I did it similar to the pictures and am very happy with the results. I didnt gain much on the top end, but low and mid range is crazy now, the motor just runs better, idles smoother and smokes more even though I had to retune, but thats ok. I consider myself above average in small engine repair, thats why I went for it. The Mach 28 dynamite has only scalloped crank cuts, but nothing on the sleeve, thats why I noticed so much increase. Its awsome and BTW I'm just a basher not a racer.