[Dragncar]

The new engine takes a different plug for me. 14 mm with 3/4" reach, 5/8 head.
I used to run Denso race plugs. The Accel brand (Denso made them) and I liked them a lot with my iron heads
But not plug is available from them that I can find. I did find one, but they had 13/16 heads and will not work with High Ports.
I have had a couple a real bad experiences with Champion non race plugs. Found out there were 2 piece electrode the hard way. On a run the bottom of a electrode was gone with the top half still in plug boot.
Junked them, never again.
Champion makes a race plug for the High Ports so I bought a plug and did the same with Autolight and NGK.
Those were the 3 I have to choose from. So I took a hammer to each one of them to see what they were made of and to also check if the Champion had a 2 piece electrode.
They are all made different and the results are Champion while not a 2 piece was the lowest quality . electrode was smaller than the others and the tip fell right off when I busted the porcelain.
The NGK was well made, but I have never been a NGK guy. I know they are great and a lot of people like them the best. The tip was solidly attached to the electrode but it was a bit smaller than the Aurolight which had the thickest one.
Champion offers a full selection of heat ranges, where I need it and hotter and colder.
Autolight offers the heat range I should need but only colder , none hotter but I am almost certain I will not need a hotter plug.
Its a 11.5-1 pump gas engine.
Cost me 15$ total for the 3 plugs but I found out what I needed to.
Pics.

[Elarson]

We used Autolite race plugs on the Grocery Getter and had no problems except a few that had a whisker on the ground strap that threatened to ground out the spark. Easy to see and easy to brush off.
We ran Champion race plugs on the Boss Bird and never were disappointed.

FWIW,
Eric

[PAUL K]

Most race shops used NGK because of their cost and the quality was good enough. When NGK decided to triple their price and gave a six week notice of the upcoming increase. Most shops stocked up on NGK plugs and are still using them. A lot of others switched to Autolite. IMO Autolite always has been a superior plug that offered something for the additional cost.

[64speed]

There is a good Engine Masters about this that just came out recently. The consensus was that unless you are running top fuel it does not really matter the brand

[Gach]

I ran Autolite’s for years, they didn’t have Autolite’s I needed so I got the NGK seems to have a better heat range. The NGK plugs look better just switching out the Autolite’s.

[Gach]

Of course doesn’t really mean anything. But I do like the NGK’s.