Pull the valve cover and look. On the intake side, near the rocker arm, It will have a big valve spring and a little valve spring if it has the jet valve. I'm at the same point myself. put a crank and rod in my 2.6 or go get a wide block 2.4 from the u-pick-it here.

Blacktero: 90 Montero Lwb V6 RS Model. 16" Toyota Alloy Rims, Dual Bouncy's; Gen II Front Rotors & Calipers; Rear LSD

Sraider: 87 Raider 2.6 base. Work yet to be done.