402 Spark Plugs? R43XLS ?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

REPO1 · 03-31-2002, 07:13 PM

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 ??

------------------
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!!

cali_surfer · 03-31-2002, 07:30 PM

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.

71GMC_3/4T · 03-31-2002, 07:33 PM

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.

REPO1 · 03-31-2002, 07:37 PM

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!

03-31-2002, 07:13 PM	#1
REPO1 Shortbox wanna-be. Join Date: Mar 2002 Location: Fort St.John, British Columbia, Canada Posts: 773	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 ?? ------------------ 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!! __________________ 1970 Chevy C20 Custom Camper 402BB Turbo 400 trans. (Slowly becoming a '70 shortbox 1/2 ton) '71 Camaro SS 402/T400 resto '97 Z28 (11.41@127MPH)

03-31-2002, 07:30 PM	#2
cali_surfer Registered User Join Date: Jun 2000 Location: Chico, CA Posts: 1,136	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. __________________ My engine is stock... trust me ;o)

03-31-2002, 07:33 PM	#3
71GMC_3/4T Weapons Of Construction Join Date: Apr 2000 Location: Colorado, USA Posts: 1,095	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. __________________ 1971 GMC 2500, 402/TH400 4.10 Daily Driver Lafayette, CO

03-31-2002, 07:37 PM	#4
REPO1 Shortbox wanna-be. Join Date: Mar 2002 Location: Fort St.John, British Columbia, Canada Posts: 773	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! __________________ 1970 Chevy C20 Custom Camper 402BB Turbo 400 trans. (Slowly becoming a '70 shortbox 1/2 ton) '71 Camaro SS 402/T400 resto '97 Z28 (11.41@127MPH)



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