Re: rear tyre profile..
I just moved up to the bigger dunlop 190/60 or 65/17 dot gpa race tire...it's the same 195/xx/17 slick. It's 13mm taller than the dot 180/55. So you may need to lower your shock a bit 6.5mm to maintain same rear height. I had to get a longer chain, rear axle was moved back about 1/4" or so, near the limit of adjustment (get a good chain that won't stretch too much) lengthening the wheelbase...so I only changed my shock height by 3mm or so. I also put some washers under the hugger bolts to raise it up a touch...may or may not be needed if the wheel is back far enough but I wanted to count for the tire expansiona at high speeds.
The beni's....More F-n Grip!!!!! If your spinning up the rear often, you will find the hastle of the change WELL worth it! Trust me! I still spinn it up but there is so much more grip. It's a heavier tire..but the bigger contact patch makes up for it. It feels planted. The dunlop guy tells me they haven't sold a 180 at a ama race in quite a while...I now understand why! You can really get on the gas harder and sooner!
Another beni is that once setup for that size tire you can switch from dot to slicks w/o chassis changes..same size.