It's a 2T/3T hybrid. 88260 is a later model EFI 2T-G head, the 3T block is probably 78mm stroke, 85mm bore for 1770CC. Have a close look at the motor, the distributor sits at a different angle and the top water outlet/thermostat is on the other side of the head relative to 18R-G.
Not a bad motor in its own right but definately not a bolt-in proposition for your Hilux!