Just chiming in to say take bonespecs advice. I installed the 4.7FD early last year in my ITA CRX along with a refresh (3 new synchros and new shift forks). I tried the Amsoil Synchromesh, the one that says it works for Honda boxes on the label, and I got a crunch in 3rd. Same with Redline. Too slippery for the syncho.

Picked up the Pennzoil synchromesh and I've done 17 races on it now with lots of abuse and not a single crunch. I don't have a plate diff so I do not use additives.