"Got Lead?" - The 1947 - Present Chevrolet & GMC Truck Message Board Network

tracterman2 · 03-01-2007, 12:51 PM

do any of you use lead substitute in your fuel...the ones with the original engines?? I know valve seats tend to dry without it on these engines...what substitutes if any have you used....do we really need to use it?? I have the original 307 with 44,000 miles on it....I wonder if I should use a substitute?? What do you all think??

williamt · 03-01-2007, 01:05 PM

I have run with and without and have not been able to tell any differance

ProStreet68SB · 03-01-2007, 04:40 PM

Since you have an older 307, I would run lead in your fuel. You motor doesnt have hardened valve seats which is bad with unleaded fuel. I forget the total reason

. but if iirc the lead acts a cushion for the seat.

mrein3 · 03-01-2007, 05:49 PM

On all the engines I've rebuilt, I've had the guy working over the heads put in the hardened seats so I can run unleaded.

IIRC, ALL GM V8s from 1971 on are OK with "low-lead" fuel.

About 1 year after I purchased my truck I had to do a valve job. #4 and #8 had no compression. When I pulled the head the valves were visibily sucked up higher in the head. I can only assume the seats were ruined. My cylinder head guy said they were junk.

So to summarize, if you have a 1971 or newer engine, or if you worked your heads over recently, you don't need the lead.

**special-K** · 03-01-2007, 05:55 PM

Heads all converted for no lead.

chevguy7 · 03-01-2007, 06:01 PM

I don't use lead in mine but I do try to burn 89 octane.

shortbed70 · 03-01-2007, 08:07 PM

The lead in fuel was to cool the valves and the combustion to run higher compression. They make a substatute for this and you can get 103 oct out of 91 gas. I talked to a vendor and he was selling a case of quarts (12) for 148.00 a case. One quart will do I think two 15 gallon tanks of fuel. If you had the older heads it will crack the valve seat or burn the guides.

tracterman2 · 03-01-2007, 09:12 PM

can you still get instead o' lead....do you guys remember this?? I remember it a long time ago..but haven't seen it in a long time

03-01-2007, 12:51 PM	#1
tracterman2 Registered User Join Date: Jan 2007 Location: Nashville, Arkansas Posts: 96	"Got Lead?" do any of you use lead substitute in your fuel...the ones with the original engines?? I know valve seats tend to dry without it on these engines...what substitutes if any have you used....do we really need to use it?? I have the original 307 with 44,000 miles on it....I wonder if I should use a substitute?? What do you all think?? __________________ I'm Your Huckleberry. You Ain't No Daisy.

03-01-2007, 01:05 PM	#2
williamt 68 just like me Join Date: Feb 2007 Location: canton ga. Posts: 142	Re: "Got Lead?" I have run with and without and have not been able to tell any differance __________________ 68 just like me

03-01-2007, 04:40 PM	#3
ProStreet68SB The Engine Whisperer Join Date: Sep 2006 Location: Ohio Posts: 770	Re: "Got Lead?" Since you have an older 307, I would run lead in your fuel. You motor doesnt have hardened valve seats which is bad with unleaded fuel. I forget the total reason . but if iirc the lead acts a cushion for the seat.

03-01-2007, 05:55 PM	#5
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,863	Re: "Got Lead?" Heads all converted for no lead. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

03-01-2007, 06:01 PM	#6
chevguy7 Registered User Join Date: Oct 2006 Location: Washington Posts: 316	Re: "Got Lead?" I don't use lead in mine but I do try to burn 89 octane.

03-01-2007, 05:49 PM	#4
mrein3 Registered User Join Date: Feb 2000 Location: Center City, MN, USA Posts: 3,253	Re: "Got Lead?" On all the engines I've rebuilt, I've had the guy working over the heads put in the hardened seats so I can run unleaded. IIRC, ALL GM V8s from 1971 on are OK with "low-lead" fuel. About 1 year after I purchased my truck I had to do a valve job. #4 and #8 had no compression. When I pulled the head the valves were visibily sucked up higher in the head. I can only assume the seats were ruined. My cylinder head guy said they were junk. So to summarize, if you have a 1971 or newer engine, or if you worked your heads over recently, you don't need the lead. __________________ '70 cab, '71 chassis, 383, TH350, NP205. '71 Malibu convertible '72 Malibu hard top Center City, MN

03-01-2007, 08:07 PM	#7
shortbed70 Registered User Join Date: Mar 2002 Location: Forney TX Posts: 4,512	Re: "Got Lead?" The lead in fuel was to cool the valves and the combustion to run higher compression. They make a substatute for this and you can get 103 oct out of 91 gas. I talked to a vendor and he was selling a case of quarts (12) for 148.00 a case. One quart will do I think two 15 gallon tanks of fuel. If you had the older heads it will crack the valve seat or burn the guides. __________________ Troy 1965 Chevy Bagged,361 sbc,voodoo cam,1.5 full roller rockers,patriot 185cc vortec heads 2.02-1.60,vortec weiand polished intake,demon carb my truckhttp://67-72chevytrucks.com/vboard/s...d.php?t=332884 Big Red Dog build http://67-72chevytrucks.com/vboard/s...d.php?t=572274

03-01-2007, 09:12 PM	#8
tracterman2 Registered User Join Date: Jan 2007 Location: Nashville, Arkansas Posts: 96	Re: "Got Lead?" can you still get instead o' lead....do you guys remember this?? I remember it a long time ago..but haven't seen it in a long time __________________ I'm Your Huckleberry. You Ain't No Daisy.



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