For the Standard Denso spark plug:

stock # 3046
plug # W20EPR-S11

For the Premium Denso spark plug:

stock # 3116
plug # P20PR-S11

For the Iridium Power spark plug:

stock # 5306
plug # IW20

I am at work right now and I just looked in our Denso book for the application under a 1988 G54B Mighty Max...its the same for the Montero/Raider.

I've always used the standard NGKs in all my vehicles and they work fine. I don't think anyone could tell in a back to back test drive with the standard plugs compared to V power (in a rig with a healthy ignition system). I sure have never noticed any difference.

I prefer a spark plug called "Truck Plugs" They must be a hotter plug because they do not foul with oil or rich fuel.
I have run them for 150,000 between spark plug changes.
Bob Shaw

Don't get me wrong, I probably could run my NGKs alot longer, I am just psyco <img src="/forums/images/graemlins/scared.gif" alt="" /> about preventitive maintanance. I change my coolant, trans fluid ,gear oil in my xfercase and diffs once a year. My oil every 3mo (1500mi)w/Mobil 1 synthetic. Pack my wheel bearings every year, bleed my brake fluid every year. You get my point. The changes may not be nessesary, but I don't like surprises. Everything gets checked after a long trip and wheeling. Why do I do it? Because I can, and fluids can tell a story.

Well, I adjusted the oil level. It seems a bit better now. I might run a bit hotter plug as well. The plugs I took out looked PERFECT. Not cruddy, not too hot, not too cold. This motor has excellent compression, and doesn't use oil at all as far as I can tell.

More time will tell I suppose. I did notice quite a bit of gunk in the (brand new) PCV. I cleaned it out and drove it 40 miles. That's all it'd been driven. It again was clean. I dont know if it was the oil level or what... but... hey now it's better so... I don't care, lol. It's not any worse than my 98 Voyager (yes, I drive a van - and I like it) now.

The owners manual says 5.2 quarts. <img src="/forums/images/graemlins/kewl.gif" alt="" />

Yep. What a revolting predicament.

There are many good plugs on the market. I was just recommending a good non fowling(sp) plug for reliable off road use or in oil burning vehicles.
Bob Shaw

Non-fouling. Ok, such as? (not trying to be a wisev <img src="/forums/images/graemlins/butwiggle.gif" alt="" /> - I wouldn't ask if I knew already).

Somebody makes and sells a recessed/shrouded electrode plug for SBC's that avoids some oil fouling from sorn guides by shielding the electrode from the drip. Don't work. NGK's are my pick, base plugs, slighter tighter gap than spec.

I used to own a spark plug cleaner (12v glass bead blaster) and would run plugs until the center electrode sank to the porcelin, cleaning and regapping, and got 50k+ out of a set, with no real misfires. Those were Bosch std. plugs, back when Bosch still made a good plug, in a 12.5:1 compression 7500rpm Fiat 1598cc dohc I4.