Does anybody here run Autolite's XP105 Iridium plugs?
I can get a set of those for less than $40.

Car is a stock '97 Z28 approaching 44k miles. I don't have any issues with my current stock plugs/wires yet. Is it time to change the originals?

Since I'm not planning any heavy mods, should I stick with OEM wires (buy a a new set)? I've also heard about Taylor 8mm replacements but any other suggestions will be greatly appreciated (I feel ac-delco's are a bit pricey).

Thanks

 

The stock plugs were AC Delco's. They were double platinum and had a tendancy to shed one (opens gap to 0.070") or both (opens gap to 0.090") of the platinum pucks. They were intended to last 100K miles, but I'd check them.

The NGK Iridium version of the TR55 seems to be popular. I've had good luck with the Autolite standard plugs (both the 104 and the 103), but I've never tried the Iridium.

Stock wires are fine. I had an issue with the Taylor 8mm's. Dealer replaced them with 7mm Packards (GM) under warranty and they were fine, even running a 125-shot on top of a relatively stock engine. Currently running MSD 8.5's but its no longer a stock ignition system.

 

Thanks for the feedback.

If I go with regular copper, is Autolite 106 the correct number for a stock LT1?

I've heard the 7mm Packards are no longer available. The AC-delco newer ones are supposed to be less sturdy and have a higher resistance. Not sure if leaving the current wires in is a good/bad option.

I would like to do this right once and forget about it.

 

I'd replace the wires, since they are at least 14 years old. Not sure what I'd recommend. The MSD 8.5's are overkill, and hard to fit in the stock wire looms.

"Copper" plugs will simply not last as long as the iridium plugs. With a basically stock engine, I'd use the iridium, or a set of platinum. I use copper because I run a lot of nitrous, and platinum plugs aren't good with nitrous.

Here's a plug guide:

https://www.camaroz28.com/forums/sho...d.php?t=431689

It references a different Autolite part number for stock LT1 heads.

 

Yesterday I checked out the Iridium Autolites and noticed they were made in Mexico.
While researching, I read that the US version might be the way to go (if they can still be found). Has anybody had any issues with newer Autolites?
Any reason to think Denso or NKG iridiums are in any way better?

I also saw some AC-delco "Rapid Fires" - around $10 cheaper per set than the iridiums.
How long could those last?

Regards

 

I think it just depends on the particular plug. I've seen autolites that were made in mexico, china, and the US at walmart. When I was changing the plugs on my car after buying it last summer all of them were Ac delcos except the number 2 plug that was under the alternator. It was an autolite app106 double platinum and god knows how long it was on the car. It was still good though. Not that you will have much luck finding that plug as I haven't been able to find them anywhere.

I'm currently using NGK TR55's. I still haven't changed the number 7 and 8 plugs because I can't get from them up top but I'm probably going to change them soon and I'm seriously thinking of trying champion double platinum's. The price is right and I think they may be only plug left that is still made in the usa.

As far as plug wires I'm thinking about getting some delphi's. I'm pretty sure they claim to be the oe manufacturer(packard wire) on their website and everything I've bought from them so far has been made in the USA. Which is not true for the last several parts I've bought from ac delco. I bought a Ac delco waterpump for my grannys caddy a couple of summers ago and it said assembled in the usa from parts made in china.


http://delphi.mycarparts.net/brands/...oducts/1236831

 

I bought a set of autolite double platinum's the other day after my icm died and fouled the plugs. They were made in china and one of the terminals on one of the plugs was at a 45 degree angle. I took them back and exchanged them for some tr55's.

 

Some of the Autolites are being made by Torch, who bought some of AC's old equipment. Champions can be made in USA, but they also manufacture plugs in Mexico and India.