Just went through the same crap. Replaced Oem shifter with mgs gen 1, shifting was notchy but passable, after upgrading blower to vmp 2.3 I blew clutch had s McLeod txt installed by a shop I thought knew what they were doing..shifting got worse and worse wad so bad I had to smash it into...
if you mke the odd trip to the strip 410"s are the best but you need to have at least 28 inch tall rear tires, if not going to the strip the 373's are the answer. I went from 373's to 410's but I visit the strip with nitto NT05R 305 45 18's on the back