Preferred plugs?

As the title says, just seeing if there are any preferred spark plugs. Being a near life time GM guy and them prone for ignition problems from using anything other than AC/Delco parts just thought I'd check.

Additionaly, the truck, PCM and top end is '98, but the short block is a transplanted '94 4.0. I'm starting to wonder if there is difference in heat range or reach on the plugs as since the weather has been warming up, it started to develop a miss after running 40+ minutes or so.

For plugs on both of those years, I'd go with the original Champions...I've seen threads where these engines suffer with other plugs.

My '04 came with NGK, which have also given good service, but I don't think they were listed for the earlier years.

You'll notice a huge difference changing the plugs every 30K as the owner's manual specifies...and since the stock Champions are $2 a pop, it's all good!

Thank you sir.

I also took the liberty and checked both years and the part number #412 is the same. :cool:

And I hear ya, on every vehicle that I've owned with a mechanical ignition system I replace every item other than wires (unless exposed to tons of heat) every spring at the very least.

Ah hah hah, I fell victim to not heeding my own advise: When you get a used vehicle, go through everything, never assume it's good.

Let's see, fouled plugs, one internally rusted plug wire, and imporperly seated cap, all solved by plugs, wires, cap and rotor, and thing's running like Bin Laden from a Navy Seal team.

Also back flushed the cooling system out as the radiator was filled with well water and it was rusty and scaley.

However, I do have one concern that I can't put my finger on:

Working from the front back, the first 3 plugs were pretty much ok, normal wear. The back 3 tho were burnt up pretty good, pinkish red on the insulator. Not sure what to make of that, so in about a thousand mile I'm going to pull the plugs and read them, see if it's still happeneing.

But all in all, man what a difference when she's running on all 6. :lol:

Ha, NEVER trust the previous owner to have done their maintenance!!

I'd bet that with all the other ignition issues you solved, that the plug wear will be normal after this.

Keep an eye on your temperature gauge, with a scaly radiator that's 16 years old you may have some cooling issues when it gets hot again. There are lots of cooling issues here from folks that never changed their coolant...hopefully yours will be good to go with the tlc you've already given it.

lol, the bottom end of the motor is only 16 years old, the rest is only 12. :wink:

I'm going to ride with my prognosis so far that since the cap waasn't seated right, the rotor was creating a gap on one side and grinding the other side of the cap contact tabs created the inconsistant plug temps.

As for the radiator, believe me I'm watching like a hawk, and I absolutely hate the elbow neck they use for the filler so you can't see into the radiator itself. Anyway, it all started with a leaking cap that blew all over the air cleaner box and I nearly freaked at the rusty color of the coolant immediately thinking blown head gasket. But, filled her up and ran it and no air was bubbling up, good sign, oil clean, nother good sign. Anyway, the 'revious' owner, I knew, and he took pretty decent care of it, but always had over heating issues, and cracked the radiator once, and then finally the block (which is how it came in my possession). I only had it get hot once when the secondary fan locked up on me, problem to be looked into next.

Anyway, the short block swap was done at my brother in laws place in the country and I put one and one together when we were working on a demotlition derby car there and I was using the washroom, looking into th toilet bowl which was all rust stained, and then it downed on me and I asked "hey, did you fill that radiator up with awater from here?" eh-heh

So, I replaced the upper hose AS (for anyone else reading) the upper hose did not have a protective sheething over it and a bolt from the A/C compressor wore a concerning hole the underside of the hose. Well, upon removal, the hole was through the hoses belts. :eek:

As said, installed a flush T and backflushed her for a good hour, periodically starting the engine and letting the pump push every thing out too until everything ran clear.

Suffice it to say, heat is now awesome, go figure, and she ran all the way home about 5-10 degrees cooler on average.

And with the extra power of an 'added' cylinder, it was hard to keep from doing 80, seriously. :grin:

EDIT - And I'd love to meet the genious who designed where to put the drain cock on the darn thing. :disappoin