What Spark Plug with HEI - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**CPNE** · 09-08-2003, 09:30 AM

This has been answered before but I'm unable to locate the thread.

I have a basically stock 350 (ya I know, go figure!

) with a GM HEI and Edelbrock 650 4bbl carb as the only upgrades. I need to know what plugs and gapping to use. They guy at NAPA said there are a bunch of different plugs that can be used depending on year etc.

If it matters, it's got stock rams horns and a 3 speed manual tranny.

The plugs at NAPA are A/C Delco, but if you have another suggestion that can be bought at VIP I can shop there too.

Thanks

hgs_notes · 09-08-2003, 09:41 AM

This may not be correct, but what I did was look up the gap for the vehicle the distributer came out of. I know it was like twice as much as the stock points distributer.

HG

tom hand · 09-08-2003, 09:56 AM

Use the plugs you are using now if you are having no problems...ie they are the correct heat range. Gap them at 45 and you are all done

**CPNE** · 09-08-2003, 10:01 AM

I should have mentioned this is a new project and the plugs in the engine are probably wrong and do need replacing. The HEI is from an unknown vehicle but is the 4 wire pre-computer variety.

JimKshortstep4x4 · 09-08-2003, 10:03 AM

Since most of our driving is short trips, we run R45TSX AC plugs, gapped at .045. If you do long trips a lot, you may want to drop the heat range, (R43 or R44).

Jim

**CPNE** · 09-08-2003, 10:08 AM

Thanks Jim. That was the one NAPA concluded may be correct. And it'll be a short haul truck. Thanks

09-08-2003, 09:30 AM	#1
CPNE Resident Curmudgeon Join Date: Dec 1999 Location: NH Posts: 6,662	What Spark Plug with HEI This has been answered before but I'm unable to locate the thread. I have a basically stock 350 (ya I know, go figure!) with a GM HEI and Edelbrock 650 4bbl carb as the only upgrades. I need to know what plugs and gapping to use. They guy at NAPA said there are a bunch of different plugs that can be used depending on year etc. If it matters, it's got stock rams horns and a 3 speed manual tranny. The plugs at NAPA are A/C Delco, but if you have another suggestion that can be bought at VIP I can shop there too. Thanks __________________ Currently on or near the homestead: 67 Chevy SWB 2WD stepside 350/3 on tree (Pat's) 67 GMC SWB 2WD Fleet 402/auto (Brian's under construction) 67 Chevy 3/4 ton 2WD 402/auto (Business Hauler) 67 Chevy 1 ton dually 2WD 396/4 speed (Former business hauler, Needs TLC) 68 Chevy 1/2 ton Suburban 2WD 250 six/3 on tree (Brian's Needs TLC) 70 Chevy 3/4 ton 4WD 350/4 speed (Pat's - Disguised as a 68 GMC) 71 Chevy SWB stepside (Crushed by tree - parts donor) 72 Chevy 3/4 ton 4WD (Parts donor) 72 Chevy 3/4 ton 4WD Suburban (Parts Donor) 72 GMC 3/4 ton 4WD 292 six/4 speed (Mine - Disguised as a 67 GMC) 81 GMC 4WD Dually Dump Body 350/4 speed (Business Hauler) 82 Camaro Z/28 355/Super T-10 (Pat's toy) 93 Caprice 9C1 (Brian's Cop Car) 02 Toyota Camry (Reliable but a souless steel and plastic hulk) 2011 2SS RS Camaro M6 Factory Hurst Shifter Maybe I need to sell some of this crap Yet another Bozo with a sawz-all

09-08-2003, 09:41 AM	#2
hgs_notes GEARHEAD Join Date: Aug 2003 Location: MN Posts: 6,126	This may not be correct, but what I did was look up the gap for the vehicle the distributer came out of. I know it was like twice as much as the stock points distributer. HG __________________ If no one knows what you're doing, they can't tell you you're doing it wrong HG's Dream Car Build - Shelby Cobra Kit Build your own adjustable track bar 71 Long Fleet C/10 72 Jimmy 4x4 (Junkyard Jimmy) HG's Plow Truck '78 K35 Dually Bigass Farm Truck HG's thread of miscellaneous stuff

09-08-2003, 09:56 AM	#3
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	Use the plugs you are using now if you are having no problems...ie they are the correct heat range. Gap them at 45 and you are all done __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS

09-08-2003, 10:01 AM	#4
CPNE Resident Curmudgeon Join Date: Dec 1999 Location: NH Posts: 6,662	I should have mentioned this is a new project and the plugs in the engine are probably wrong and do need replacing. The HEI is from an unknown vehicle but is the 4 wire pre-computer variety. __________________ Currently on or near the homestead: 67 Chevy SWB 2WD stepside 350/3 on tree (Pat's) 67 GMC SWB 2WD Fleet 402/auto (Brian's under construction) 67 Chevy 3/4 ton 2WD 402/auto (Business Hauler) 67 Chevy 1 ton dually 2WD 396/4 speed (Former business hauler, Needs TLC) 68 Chevy 1/2 ton Suburban 2WD 250 six/3 on tree (Brian's Needs TLC) 70 Chevy 3/4 ton 4WD 350/4 speed (Pat's - Disguised as a 68 GMC) 71 Chevy SWB stepside (Crushed by tree - parts donor) 72 Chevy 3/4 ton 4WD (Parts donor) 72 Chevy 3/4 ton 4WD Suburban (Parts Donor) 72 GMC 3/4 ton 4WD 292 six/4 speed (Mine - Disguised as a 67 GMC) 81 GMC 4WD Dually Dump Body 350/4 speed (Business Hauler) 82 Camaro Z/28 355/Super T-10 (Pat's toy) 93 Caprice 9C1 (Brian's Cop Car) 02 Toyota Camry (Reliable but a souless steel and plastic hulk) 2011 2SS RS Camaro M6 Factory Hurst Shifter Maybe I need to sell some of this crap Yet another Bozo with a sawz-all

09-08-2003, 10:08 AM	#6
CPNE Resident Curmudgeon Join Date: Dec 1999 Location: NH Posts: 6,662	Thanks Jim. That was the one NAPA concluded may be correct. And it'll be a short haul truck. Thanks __________________ Currently on or near the homestead: 67 Chevy SWB 2WD stepside 350/3 on tree (Pat's) 67 GMC SWB 2WD Fleet 402/auto (Brian's under construction) 67 Chevy 3/4 ton 2WD 402/auto (Business Hauler) 67 Chevy 1 ton dually 2WD 396/4 speed (Former business hauler, Needs TLC) 68 Chevy 1/2 ton Suburban 2WD 250 six/3 on tree (Brian's Needs TLC) 70 Chevy 3/4 ton 4WD 350/4 speed (Pat's - Disguised as a 68 GMC) 71 Chevy SWB stepside (Crushed by tree - parts donor) 72 Chevy 3/4 ton 4WD (Parts donor) 72 Chevy 3/4 ton 4WD Suburban (Parts Donor) 72 GMC 3/4 ton 4WD 292 six/4 speed (Mine - Disguised as a 67 GMC) 81 GMC 4WD Dually Dump Body 350/4 speed (Business Hauler) 82 Camaro Z/28 355/Super T-10 (Pat's toy) 93 Caprice 9C1 (Brian's Cop Car) 02 Toyota Camry (Reliable but a souless steel and plastic hulk) 2011 2SS RS Camaro M6 Factory Hurst Shifter Maybe I need to sell some of this crap Yet another Bozo with a sawz-all

09-08-2003, 10:03 AM	#5
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Since most of our driving is short trips, we run R45TSX AC plugs, gapped at .045. If you do long trips a lot, you may want to drop the heat range, (R43 or R44). Jim



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