LS1GMCTruck

iTrader: (2)

Which direction should the electrode be pointing when tight? What benefit does this gain? Where do I obtain sparkplug shims? Thanks, Ed

Shane

direction: I've seen a post recommending that the electrode point at the *exhaust* valve (doesn't seem logical to me, but that's what it said...)...
benefit: Seems like most LS1 folks don't think it's worth the effort - though a lot of old-school hotrodders swear by it...
Shims: Shims you can get at Jegs or Summit I believe...

I'll probably do this the next time I have the plugs out...

good luck,
Shane

pimpmaro

We've been over this discussion just a short while ago... I couldn't find the link to the thread, but it was STRONGLY recommended to not use shims. Instead the recommendation was to buy several plugs and swap them around to see which line up the best. If you have to adjust the fit at all of a plug, it was decided to machine the plug down so it threads in further instead of shimming it, just because it would pull it into the recess of the cylinder head.

pimpmaro

Spark Plug Indexing Thread...

Before you start workin on this project, I'd recommend reading all through that. GL and have fun!

eallanboggs

iTrader: (1)

The fuel and alcohol guys don't do it so why should you? Just get yourself a MSD Pro 44 Mag and you won't have to worry about indexing ever again.

gMAG

iTrader: (1)

Can't say that I've ever fretted over plug indexing, but, I do enjoy the subtleties of refinement.
The MSD does send a much higher voltage, and longer duration spark, but it doesn't make much sense to me to inhibit it with the ground tip.