I haven't raced my 08 yet (so. cal. desert), but after talking to guys on the same bike at the H&H national yesterday it's obvious the stock tank aint gonna get it. My son has a Clark 2.6 on is 08 YZ that is very slim. IMS 3.1 is wider thru the knee area. Both would require YZ shrouds. I need a solid 50 mi. range to cover our race lengths and have some left just in case. What range are you guys getting on the stock tank, and any using the Clark tank, what range are you getting out of that? Thanks for any info.