I see no reason why a rodeo transmission wouldn't fit straight in - here in the UK we have the Frontera with the Isuzu V6 same as the JDM VX - having examined the whole transmission i have discovered that a donor manual V6 frontera transmission would bolt straight to the VX power unit - the frontera transmission is SOTF like the JDM VX so giving 4WD by button and low range as well
surely a US rodeo V6 is the same as a frontera and a rodeo ecu would fit the VX as a swop sorting out the auto transmission problems
the transmission comes with a 'dual mass' flywheel and handles speeds up to 130 mph easily
cheers
Steve