Found this info on the Caltex 'Find the right oil" site (www.caltex.com.au)
EVINRUDE
175.0 h.p. 175 V-6 FICHT (1998-2002)
Motor
SUPER OUTBOARD 3
(See Note 29, 40)
Gearcase
SYNSTAR GL 75W-90
(See Note 48)
NOTES
29 Manufacturer recommends the use of "OMC FICHT RAM Injection Oil".
40 Fitted with Electronically Controlled Direct Injection (FICHT), put recommended lubricant in oil reservoir.
48 May also use THUBAN GL5 EP 80W-90. Power tilt/trim units or power steering, use TEXAMATIC 1888 or AUTOTRANS FLUID IID.
Looks like Caltex make something that fits the bill.
Cheers WG