I was having some problems with my third gear syncro: ie. It wasn't doing anything. I was grinding every time I went into it. It turns out that when I had my last clutch replaced, they drained all my liquid gold out (BG Syncroshift 2) and put shit in. So I descided to try somthing new.
-50/50 mix of Redline MTL and Redline MT-90
-One tube of Mollyslip manual transmission additive
The problem I was having before, was the fluid was heating up too much, and causing the syncro not to do anything.
With the new fluid, it takes a while to warm up, and is a bit notchy when cold, but no more grinding. I highly recommend this mixture, and the mollyslip seems to have made a pretty big difference.