If you're interested in replacing them with OEM check out:

https://www.mitsubishiparts.com/oe_parts_catalog.html

You might as well go for a shock that has appropriate valving for your vehicle's weight. I think they are under $40.

'02 Montero: OME suspension, ARB front bumper, homemade skid plates & spare tire Blitz can mount, extended diff. breather, K&N air filter, Optima Yellow Top, BajaRack, IPF lights, Goodyear Duratrac 265/75/16's, RUD 4x4 Grip chains