Dattman wrote:
The kits are shipped with identical syncro's these days, originally first gear has a keyslot of 8.2mm/0.32 and 2nd has a 9.6mm/0.38 wide keyslot.
I just rebuilt a GT box using the Anaheim Gear bearing and seal kit which was all good Japanese bearings. But the Synchro kit I got separately from Ebay (different vendor) had identical 1 and 2 synchros. Within 20 shifts it was already grinding 2nd gear!
I had to pull the box, split it and press the counter shaft apart. I reused old 1 and 2 synchros from a low mileage JDM box and it works great now.
I STRONGLY urge people to try to find the correct 2nd gear synchro, unless you need the rebuilding practice.