TR O/D Gearbox Oil

[searle@indigo.ucdavis.edu (Philip A. Searle)]

Any thoughts as to a suitable oil here in the US for an overdrive TR4 gearbox?
I used to use Castrol ST-90 in my Spitfire 1500 O/D 'box. Is this available
in the US anywhere?
The only stuff I can find in the shops around here is the normal hypoy
EP-90 etc gear oil, which isn't recommended for overdrives.

Thanks in advance

Phil Searle
WWW:  http://www-chem.ucdavis.edu/~searle