ATTENTION: This applies to Vortec and some aftermarket heads only not to "stock" heads.

I posted my situation in the Alternative Port Intake section, you can read it HERE . So I thought I would post a few pictures of what the WRONG and RIGHT spark plugs look like in the combustion chamber (difference between an ACDelco R45TS(taper seat) and R42LTS(long taper seat)). This will hopefully make some of you aware that there can be a huge difference in reliability and even performance for using the old "stand by" plugs.

The first picture is the outside pic of the plugs, top one is the CORRECT R42LTS and the bottom one is the INCORRECT R45TS (no L)

The second picture is of the combustion chamber this is where the difference is obvious the R45TS does not even break the plane of the combustion change, the electrode is in the threads for crying out loud. The R42LTS on the other hand is well into the combustion chamber as it should be.

The third picture is the same situation of the second picture just a different angle.

 

of course those are the vortec heads the need the plugs for vortecs or fastburns hear the have pretty much the same chaimber

 

You scared the crap out of me for a second - I always used normal R45TS plugs since that's whats called for by the factory.

You need to specify WHICH HEADS those plugs are "THE" right plugs for.
Vortecs eh? Ok, then for those of us not running vortecs, we can disregard this. Or.... which heads are those?

 

Thanks for pointing out I didn't specify which heads this situation occurred on, I believe I have resolved that issue now.

 

I just ran outside right now in the rain to check mine and sure enough im running Delco R45TS in my vortec heads!
THANK YOU

 

Similar situation with the AFR Eliminators.
I have to run gasketed long plugs in them.