Actually I prefer the car cams for towing, much more torque in the 3-4K range.
The Montero never got the 3.0 DOHC, they got a 3.5 DOHC. If you get one of these with its wiring, try it as is. It may be enough power for you. It is close to 100 ft lb more torque than what is in your Montero now.
Any of the later SOHC 24 valve engines are not a bad choice either.

Cheers, Charlie
If It ain't broke, Modify it!
87 Montero turbo Converted back in Spring1989
95 Montero SR 3.8 DOHC Only one?
93 Pajero 3 door 6G75 Mivec with paddle shifted 5 speed
Then a Gen2 SR with full coil independent suspension.