Spark Plugs???

Meldog · February 17, 2003

I have a 94 GMC Sierra 2wd 350. I have Bosch +2 Plugs in it right now. However, I am putting on a MSD 6A Ignition. I was told that NGK plugs are what you want to use for maximum performance, but those plugs come stock in Jap cars. I am also wondering if I should get to wires also? I have stock ones right now. Just wondering what else people use.

thx, Meldog

americanmuscleman · February 17, 2003

I'm using Bosch Platinum plugs (don't know the part number off hand) gapped at .035" (the factory TBI 350 setting). They aren't the +2's though. I don't know if you have headers on your truck, but I run 8mm Tayler wires over my valve covers because I have headers. I had to custom cut my wires to do that. If you have stock manifolds on your truck, you can just buy standard SBC wires with 90 degree boots.

I used 7mm SpiroMax wires before, and they worked well. These trucks really don't need a performance wire, I just run one anyway. You might see very small gains running a performance wire over running a stock GM wire. My guess is performance wires are only worth about 2hp on these trucks.

NGK's are good plugs too. I run those in my Camaro and really like 'em. The differences between brands are hardly anything. I would just make sure you put in platinum plugs. They extend plug change intervals, and are supposed to produce a better spark.

Just my 2 cents

SilveradoWV · February 18, 2003

I was told that NGK plugs are what you want to use for maximum performance, but those plugs come stock in Jap cars.

NGKs come stock in new Silverado's!

mnstrmdnss · February 18, 2003

cant tell you what plugs to use, but i can tell you that your gonna need new wires. i have an msd ignition in my truck, and the first warning they tell you in the instructions is to use a good quality spiral core wire, NOT a solid core wire. since your getting new plugs and an awsome hot ignition module, id get the msd super conductor wires, anyway.

TarheelZ · February 18, 2003

cant tell you what plugs to use, but i can tell you that your gonna need new wires. i have an msd ignition in my truck, and the first warning they tell you in the instructions is to use a good quality spiral core wire, NOT a solid core wire. since your getting new plugs and an awsome hot ignition module, id get the msd super conductor wires, anyway.

I agree completely. I had the MSD on my '99 ZR2 with a set of Taylor spiral wound wires and was thoroughly impressed. Others with the hotter ignition and solid core wires weren't as happy!

Use good wires as well as good plugs and you should be pleased. MSD tech support told me the factory AC-Delco plugs were as good as any others so that's what I used with my MSD 6A.

Good luck!

Meldog · March 5, 2003

well i got the msd super conductor wires with NGK plugs...

thanks for the input

Meldog

silversport · March 9, 2003

Anyone use the new AC/Delco RapidFire platinums for the LS-1 based motors??? Either the 346ci LS-1 or the 325 (5.3)???

I am very interested in these plugs but get conflicting numbers (I believe #12 is the proper plug)

Any help would be greatly appreciated.

Indy SS · March 11, 2003

According to www.ac-delco.com #12s Rapid Fires are right for the 5300 Vortec. My '00 has 45K on the odometer and I plan to install these plugs this weekend w/ a new set of MSD 8.5mm wires. I think they will perform better than Platinums and will definitely cost less.

silversport · March 12, 2003

IndySS:

EXCELLENT!!! :thumb: lemmee know how you like 'em...I am sure they will be good, I used the older style non plat rapidfires in a car a while back...I plan on putting these in my ls-1 as well. Thanks for the reply. :hail:

Indy SS · March 16, 2003

Bill,

Rapid Fires and MSD wires installed as planned. I checked the gap on all 8 before installing, only a couple that were not dead-on .060 and adjusted them accordingly. The plugs that came out were all normal w/ the expected brownish haze on the insulator. I tried 'indexing' the #12s to optimize the combustion chamber efficiency but that didn't work out as easily as I had hoped, I was only able to get half of the plugs pointed in the right direction.

My truck started and idled good before, but it sure seemed that it started quicker and idled smoother after the new plugs and wires went in. Throttle response was better for sure.

If I see any improvement in mileage, I'll post again. BTW, dealer list is $7.16 each. I asked my new GM parts man for a 'nice guy' discount and got them for $4.06 a piece, so it was definiately worth asking for a break.

:thumb:

silversport · March 19, 2003

Bill,

Rapid Fires and MSD wires installed as planned. I checked the gap on all 8 before installing, only a couple that were not dead-on .060 and adjusted them accordingly. The plugs that came out were all normal w/ the expected brownish haze on the insulator. I tried 'indexing' the #12s to optimize the combustion chamber efficiency but that didn't work out as easily as I had hoped, I was only able to get half of the plugs pointed in the right direction.

My truck started and idled good before, but it sure seemed that it started quicker and idled smoother after the new plugs and wires went in. Throttle response was better for sure.

If I see any improvement in mileage, I'll post again. BTW, dealer list is $7.16 each. I asked my new GM parts man for a 'nice guy' discount and got them for $4.06 a piece, so it was definiately worth asking for a break.

:thumb:

INDY SS

Thanks...I have 2 sets I picked up on a closeout at Wal-Mart and was hoping I bought the right ones...I'll have to give 'em a try.

Thanks Again!!! :thumb:

dukbludvl · March 20, 2003

I am thinking about replacing my stock plugs with Champion Copper Plus. Will there be a problem with me doing this and leaving the stock wires?

Also, when I do replace the wires, which wires should I get to go with the plugs.

I would like to replace my plugs now (50K miles), and wait til 60K miles for the wires, then replace plugs every 30K miles and wires every 60K after that.

Just want to make sure I won't do any harm to anything running the Champion Copper Plus plugs with stock wires.

Also, do any of you think I should stick to platinum plugs instead? If so, why?

Thanks for your help on this.

QIKSILVR · March 20, 2003

Anyone running NGK Iridium plugs? I know they cost alot. Which is a better plug...NGK G-Power or the VX Platinum?

TarheelZ · March 20, 2003

Dukbludvl, you should be fine doing what you're describing. I'm using the Champion Copper Plus and I really like 'em. They should work fine with the stock wires and ignition on yours! :thumb:

Indy SS · March 20, 2003

Anyone running NGK Iridium plugs? I know they cost alot. Which is a better plug...NGK G-Power or the VX Platinum?

I ran NGKs in my LS1 Camaro with good results. At that time, the comments were G-Power's were for performance and the VX's were a VERY expensive Lifetime plug.

Lifetime plugs: IMHO.