Put what the factory recommends in it and quit worrying about it, I've seen more transmissions screw up and more shift problems because of the wrong fluid than anything else out there.
Instead of brass synchros many of these transmissions use a material like you would find in an automatic on the friction disc, saturate them with the wrong fluid and you get to rebuild it. The only thing we do different in the race car is use a synthetic equivalent of the same spec, mostly because of the heat generated, which BTW we also have coolers on the transmissions.
Instead of brass synchros many of these transmissions use a material like you would find in an automatic on the friction disc, saturate them with the wrong fluid and you get to rebuild it. The only thing we do different in the race car is use a synthetic equivalent of the same spec, mostly because of the heat generated, which BTW we also have coolers on the transmissions.