Thread: Spark Plugs for Vortec?

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Thanks, it's exactly the info I was looking for. However, I have a question on reach. I did a little more research and I keep coming across .708" reach as opposed to .750" given in your post.

The reason I ask is because I've seen some specs given as R44TS. You do say "typically use a 3/4" projected nose" which translates to a R44LTS, I think.

Are we talking a performance issue between the two or crash-bang?

Thanks,

DoubleSun

On AC plugs, prefix and suffix letters are used to identify a specific type plus the numbers relate to thread size and heat range. R44LTS breaks out as:
R = Resistor
4 = 14 mm Thread
4 = Heat Range
L = Long Reach, 3/4" (19 mm) reach, (14 mm) thread fineline (which these plugs are)
T = Taper Seat
S = Extended Tip

With a stock HEI you can run 0.040 or 0.045 inches of plug gap. A larger gap has the advantage of more complete burn of the air and fuel mixture, but it also takes more power to get a spark to jump a large gap.