Another thing....
The p5 has so much torque that you don't have to lean it up to get power, it runs fine a little fat here or there, and it never flames, if you are on a slick track you can fatten up the top a little and get the bottom just perfect with a low idle and it just runs great, and if the track is high bite or loamy and wet it can be tuned to scream and account for the extra rolling resistance. I would like to get a p5xls and have it modded for more top end and fuel mileage if that's possible, that would be the best of both worlds....If it seems to top out early due to the torque you can gear up one tooth on the bell for larger tracks and go back to the stock gearing for medium or smaller tracks, or up to reduce a bit of torque on slippery tracks...With all that torque it helps to go thicker on the center diff oil too, i use 10,000 in my 808 it seems to keep the center diff fresh longer during long mains, and it clears jumps better too. Try the mc-8 plug it seems to work great in that engine, just my experience....I try to go as cold as possible while still getting great idle and so on...So the medium plugs work good, the nova 6 special plug is ok, it lasts a long time, but the mc8 just keeps it running during pit stops when cold gas hits it during the long main. It runs around 200-225. Silly consistent over the gallons.....