FAQ: Which Spark Plugs & Ignition Wires should I use?

That sux. What kind of plugs did you use?

Had NGK platinums still in perfect shape.

You mean to say that you run a Riviera website and your grandpa has a bone stock Rivi?  

Nothing wrong with a stock Riv. I like mine modified. He's happy with the original set-up.

Just ordered a fresh set of Packard/Delphi wires from RockAuto for $26 w/discount. Only 1 set remaining at this price!

So my supercharger is about to be removed and I figured might as well do plugs and wires while its off. I'd like to do the copper 104s but it looks like a task getting at the rears so I might just get the platinum 104 so I can leave them in longer. Any tips on getting at those rears?

h20man wrote:

So my supercharger is about to be removed and I figured might as well do plugs and wires while its off. I'd like to do the copper 104s but it looks like a task getting at the rears so I might just get the platinum 104 so I can leave them in longer. Any tips on getting at those rears?

Use a plug socket mated to a short (1.5") wobble extension for the rears.

AA wrote:

Well I'll be a sonuvabitch. Knowing good and well what could happen, I went and tried NAPA's Beldon brand ignition wires on my Grandpa's '96 SC Riv. He'd been experiencing that pulsating hesitation we commonly see with these engines around 100-150k, when the wires start to wear out. I knew it was the wires, so I drove 300 miles to do the job, but I didn't have time to order the OEM Packard/Delphi wires, so I bought NAPA's "best". The sales clerk told me he'd "never seen a pair returned for any reason." They weren't cheap, and I thought they would be good enough for Grandpa.

Well, they weren't good enough. After a month of trouble-free driving, got a call. Same problem again. He got it scanned - multiple misfires. The guy at NAPA is about to get his "first" returned set of Beldons from us!

I can't believe it. We preach and preach about OEM wires being the best, and I thought maybe this time I'd get lucky with a solid brand from NAPA. Nope. Sorry Grandpa, and shame on me! I'd say lesson learned, but I knew better.

    

Order placed. Heading out to fix the problem when they arrive. So frustrating!

PS - spark plugs looked good as new. We re-gapped them and reinstalled. The car ran completely free of misfires for 4-5 weeks.

The 3800 NA uses the same wires, they work ok in that application. The coils on the SC Riv are MUCH higher energy and they turn the Belden wires into plasma at the crimps.

What do we gap the plugs at? What are the part # for the stock replacement plugs? Aren't they supposed to me some special 100,000 mile plugs?

I do mine at .055. Everyone recommends copper AL104's. They're not stock (2 ranges colder), but seem to be the plug of choice for any 3800 SII owner (especially if you're going to mod).

Advance Auto Parts has that spend $50 get $25 off your next $50 purchase option. Getting a couple thermostats 180 summer 195 winter and gaskets. Also want to change my spark plugs soon. Looking at the Autolite Double Platinum for $2.56 each (after $2 rebate). Should I get the APP606 or APP605? Not wanting to change plugs often, and I drive pretty conservatively these days   . Will use the $25 coupon to get a new set of wires. As always, many thanks for the sage advice .............

matt270avian wrote:

I do mine at .055. Everyone recommends copper AL104's. They're not stock (2 ranges colder), but seem to be the plug of choice for any 3800 SII owner (especially if you're going to mod).

I noticed awesome KR reduction when I went from 605s down to 104s. Thanks again, Scott!

Choices on spark plug wires   ???

Bosch 09377
Delphi XS10255
Denso 671-6052
ACDelco 746R or 9746R any difference

Also should I get some heat shields for the boots?
Didn't know if the ACDelco #8006 would work or recommendations .......
As always, many thanks for the sage advice !!!

Of those, I'd chose the ACDelco first, Delphi 2nd. I would use the others.

GM part # 12173547 is the 746R set. That's the proven 100k mile solution. Don't be surprised if these say "Delphi" on the wires! I believe they manufactured or supplied them to Delco, at least in part.

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Very good, that's what seems to be best. Will be using the Autolite APP605's decent price with rebate $2.30 something each. I know   probably should go with the coppers, but hoping it will be awhile before I do it again. Pretty sure it has the original wires and plugs at 105K. The Infinity speakers (4) are awesome, also very pleased with the 180 thermostat that were suggested. Also ordered a set of heat shields for the boots. My back set has factory ones, but the front set have no shields. Worried about heat from the header damaging the boots and top of wires. Couldn't find a thread about this, but did see a couple pictures from members with heat shields on the front wires and one that had a shield over the front header. Will update results, and take some pictures when I have everything and finish.

My OEM wires failed at 120k miles. They are great wires, but almost like clockwork need replaced at 100k-120k depending on the condition of the rest of the ignition system. Having coils and plugs in top shape, and taking car to keep wires routed away from the manifolds and sharp engine parts will give the most life.

The heat shields are a great idea. My fronts also came without shields. I found a set at a scrap yard for free. Glad things are working out at minimal cost to you!

AA wrote:

My OEM wires failed at 120k miles. They are great wires, but almost like clockwork need replaced at 100k-120k depending on the condition of the rest of the ignition system. Having coils and plugs in top shape, and taking car to keep wires routed away from the manifolds and sharp engine parts will give the most life.

The heat shields are a great idea. My fronts also came without shields. I found a set at a scrap yard for free. Glad things are working out at minimal cost to you!

Many GM engines have the plug heat shields, you'll find them on the 3100, 3400 as well, on the plugs on the rear bank over the exhaust. Some pick-and-pulls will give them to you... just saying...

Try Magnecor wires, http://www.magnecor.com, they were on here trying to sell 10MM wires a few years ago, you can find the thread if you're interested -- point is the 7mm or 8mm wires are just fine for the SC Riv. I have a set of the 8MM wires on my Riv, they have been on for over 150 K miles and by all appearances and testing are fine.

Albertj

Surprised GM seemingly omitted the factory heat shields on the front bank. My concern was the heat from the header would in time damage the boots. Picked up a set (6) of those flexible shields for $15. There 6" inches, more than enough to cover the boots and tops of the wire. I saw one or two pictures from some other threads where members had put the shields on the front, and one that had a shield over the front header itself. Might still pick up the factory ones for the front 3, and use them with the sleeves. Will post before and after pics when I have everything. As always, many thanks   ............

FYI, for anyone looking for spark plug shields, I found these OEMs on Amazon. A little pricey, but they are brand new:

http://www.amazon.com/ACDelco-8006-Spark-Plug-Shield/dp/B000K04C36/

AA wrote:

FYI, for anyone looking for spark plug shields, I found these OEMs on Amazon. A little pricey, but they are brand new:

http://www.amazon.com/ACDelco-8006-Spark-Plug-Shield/dp/B000K04C36/

Yes those are the shields... but no kidding if you go to a pick and pull and get them off another GM 6 they will be fine and cost you little or no $.

Albertj

Finally got around to doing the plugs and wires   . Not too bad, had access to a lift and getting to the back 3 was fairly easy. Put in a set of Autolite APP 605's, New Dephi XS10255 wire set, and spark plug boot/wire shields for the front. Not sure if the NGK 24504873 plugs and Packard wires were original or not? Thinking they were though, and at 105K glad it's done. Alittle more pep in the step too   .................

https://i.servimg.com/u/f39/18/85/12/35/dscn0213.jpg

https://i.servimg.com/u/f39/18/85/12/35/dscn0215.jpg

What were the original plugs that came in our cars from the factory?

Not sure if there's a definite answer. I had assumed ACDelco, but almost sure I pulled a set of NGKs out of mine at around 30k miles.

OE Equipment are Iridium Delco plugs.

GM P/N 12568387
Delco P/N 41-101 <-------can be bought at any parts store

No clue why there's 2 different P/N's, but they're both the same exact plug.

Ah. For some reason I thought they would've been Autolite 606's. That's what I just pulled out of my car. I was happy to see none had oil or coolant on them. Just vastly different gaps. One had a gap of .080" and a couple others had ~0.050". The others were above that.

Maybe they weren't gapped by the previous installer. Also, Autolite copper plugs' electrodes wear pretty quickly. I change mine out about every 20k miles. I see similar gaps to what you're seeing.