Non-Projected Tip Spark Plugs for Stock Heads

[motorhead]

Just as the subject says I am looking for some non-projected tip plugs to fit the stock heads on the LC2. I currently have NGK UR5s in the engine and they were working fine. However, logic states that we should be considering non-projected tip plugs... hell, my LSx cars and Vortec headed SBC all use non-projected tip plugs from the factory.
 
So if you can post up some part numbers and heat ranges it would be appreciated.

Cheers!

[ULYCYC]

I ran them with no noticeable difference in performance or life.  With AC Delco drop the "S" in the PN# and that non-projected.
R43TS will be a R43T or R42TS will be a R42T.  I never tried NGK non-projected but I'm sure the results would be close.  I'm talking about street and drag racing. Auto-X may have different results.

[motorhead]

That's part of the problem for me. Street driving and drag racing place different demands on combustion than auto-x does. The funny thing is that while my car can (usually) support 30psi, it never sees that kind of pressure on the normally short straights of an auto-x course.

So a slightly hotter plug, that won't foul from frequent throttle dumps is preferred.

[ULYCYC]

Leave the plugs alone and add a degree or two of timing when you auto-x.   

[Steve Wood]

the projected nose should be better for this.  The NGK's are good plugs but not available in as many ranges.  I would try the stock factory plug for this use...

44TS

[motorhead]

After much deliberation I ordered the same as I had (NGK UR5s); despite the projected tip concerns I have had really good success with these plugs over the last few years (both auto-xing and running 29-30psi).

I'll gap them at 0.032" and stab 'em in.

[$1987 GN$]

If you are that concerned index them.

AJ___

[motorhead]

I'll index you!

[$1987 GN$]

I'll index you!

Please do, I might feel better.

AJ___

[motorhead]

For the sake of comparison here are some plugs I had laying around. Note how projected the NGKs are by comparison to the Delcos. And you can also see how the electrode is the same thickness on the "CR43TS" Delco and "UR5" NGK. The "TR" series plugs are for LSX motors.

Oh and check out what the 4 year old UR5s that came out of my Buick look like (that is their order L & R from the engine) after having had spent a year in my old Z28. LOL!