I'm building a sled to run in 700 and 800 improved. I will step into Pro Stock 700 and maybe 800 as well for track time. My question is, do I have to meet the rgulations in Pro Stock to enter that class? Mainly having a sheet of steel fastened to tunnel. Also can I install a smaller fuel tank inside my stock one and still be legal in improved? The wieght in 700 imp is 750 and 775 in 800. Do I add wieght to run 800? Also I.ve heard they might be upping the min. wieght in pro stock to 650. Is that all the classes or just 1000? *Thanks, Mark.

You have to run the rear tunnel enclosure(either aluminum or steel in improved now anyway. So I did my 600 improver already last year. You have to retain original fuel cell in improved only, and long regulation ski's. But Pro you can switch ski's to mod shortie type. And smaller fuel cell can be in stock shroud. You have to add weight to run improved 800, it sucks, but it is the rules. The 650lb is for either 800 and or 1000 cc. You'll have to wait to hear new ISR rules. You also have to have better clutch enclosure for improvers.

Are these ISR rules for drag racing or radar running ? Or are these rules being applied to both ? *http://www.snowmobileworld-s2.com/forums/iB_html/non-cgi/emoticons/confused.gif

Drags. Check the Speed Runs out. Some groups have different rules for mod sleds.