Synth
Redline MTL
Penzoil Syncromesh
Ford Honey (but it's $$$)

Dino - syncro problems already
ATF+3 or ATF+4


ATF will never protect like a gear oil will but if you have issues already you don't want to use synthetic.

2000 SVT #674 13.47 @ 102 - All Motor! It was not broke; Yet I fixed it anyway.