402 Spark Plugs? R43XLS ??
 

R43XLS spark plugs. These are quite long, and use the gasket as the seat, not tapered seat. Does this sound right? Are these the right plugs?


Reid

p.s. what gap to use when upgrading to a HEI ??

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Sylvan Lake, Alberta, Canada

1970 Chevy C20 Custom Camper
#s matching 402BB Turbo 400 trans.
Air conditioning, power steering, manual brakes.
73,600 Original Miles!!

The 'XLS' are 13/16" socket, gasket seal NOT taper seat, 3/4" 14mm thread. If that combination fits your heads then good. I will say if you want to go with an HEI you might want to try hotter plugs. I have Edelbrock heads and I use R45XLS. I think R45 are what GM recommends for HEI ignitions.

Doesn't sound quite right. Did you take them out? I run R44T in my 71 402. It had tapered seats. But then again, mine might not be the original heads.
Also, judging from your road trip post, you still have points, so you would want something you can gap to .030 - .035.

Thanks for the replies. The reason I ask, is to know for sure what kind of seat the heads had in '70. Mine do take the washer. Is this correct for that year?

As for the gap, I do still have points right now, but I am installing a HEI in a day or so. Those damn points have to go! http://67-72chevytrucks.com/board/ubbhtml/smile.gif