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Old 07-13-2007, 01:31 PM   #1
69 camper custom
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Can I run unleaded gas

Can I run unleaded gas in my 1969 GMC Custom Camper or will it cause issues. Also last weeked I was on a cruse with my truck and it was over 100 outside and my truck would fall on its face if you got on it real hard. Do you think that was from the heat??
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Old 07-13-2007, 02:21 PM   #2
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Re: Can I run unleaded gas

I run lead substitute in my '72 K5. I have always considered it cheap insurance with leaded heads.

I forgot to add the lead substitute on a trip over the pass a couple weeks ago. I heard a definite ping when loading the engine at part throttle. The ping went away on the next tank full with additive driving the same trip. So, I feel it definitely helps my rig and straight unleaded could be the source for problems for you. Give it a try.

Of course, this assumes your engine has original engine with leaded heads, proper tune and you know all about compression, cooling, timing, etc...
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Old 07-13-2007, 03:51 PM   #3
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Re: Can I run unleaded gas

That was the same question I asked in my first post here many years and posts ago. I never worried about running lead and didn't have any problems prior to swapping out my 307 for a 454. However I'm pretty certain my 307 had been rebuilt prior to me buying it.
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Old 07-13-2007, 04:06 PM   #4
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Re: Can I run unleaded gas

Unleaded gas will ruin your valve guides and exhaust seats. I had a set of 70 LT/1 heads off a Nova and converted to unleaded with new hardened exhaust seats and brass valve guides. leaded gas used to act as a lubricant for all that stuff. There doing the same thing with diesel in cali well similar we now have a fuel (diesels) with only 15 ppm sulfer or less, the sulfer acted as a lubricant in the fuel, I have been using a lubricant additive made by my pump manufacter (stanadyne) to help with this issue

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Old 07-13-2007, 04:07 PM   #5
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Re: Can I run unleaded gas

If you know anyplace you can still get leaded gas let me know. I think unleaded is pretty much your only choice. Even lead substitute additives don't have any lead in them. I would just run it and if you eventually have wear just pull the heads and have hardened seats installed then you are good to go.
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Old 07-13-2007, 05:22 PM   #6
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Re: Can I run unleaded gas

its probablly been running on unleaded gas for well over 25years so i'd think anything that would have failed due to gas is long gone
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Old 07-13-2007, 06:59 PM   #7
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Re: Can I run unleaded gas

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Originally Posted by cdowns View Post
its probablly been running on unleaded gas for well over 25years so i'd think anything that would have failed due to gas is long gone
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Old 07-14-2007, 01:32 AM   #8
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Arrow Re: Can I run unleaded gas

What do you guys think about using a higher grade gas say 94 octane. I go to Chevron and use #1 which is 94 octane with an added fuel additive called Techrolene

esll.
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Old 07-14-2007, 05:52 AM   #9
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Re: Can I run unleaded gas

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Originally Posted by bdozeraz View Post
If you know anyplace you can still get leaded gas let me know.
www.paddockparts.com
has it -- Max Lead 2000 Octane Booster. Real tetraethyl lead. It's spendy: $33/ gallon, but 12 Oz. treats 20 gallons... $9 for a quart.
Back when you could get it over the counter at checker auto [maybe 15 years ago] I ran it in a (then) aging 292. I got a speeding ticket out in the sticks. That old L6 thought it was back in the '70s.
I was tempted to get some again when some snooty yuppie in a $1500 bicycle faked a cough at me at a stop light. [He was all over the road, too maybe provacatively so]. Like I'm not "green" enough. I'll just tank up with that stuff an double clutch all over their El Tour route. Suck on that M_____F-----s!
Since I rebuilt with stellite valves in the 292 I don't really need it.
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Old 07-14-2007, 06:15 AM   #10
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Re: Can I run unleaded gas

I agree with just run it until it smokes on start up,then have heads updated.They may have been done in the last 25 years or so anyway.Why piss money away on additives?.
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Old 07-14-2007, 09:29 AM   #11
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Re: Can I run unleaded gas

The whole thing is kind of overblown IMHO. I started wrenching in the late 70's and this was an "Oh My GOD!" kind of thing and we all started getting wired about "Stellite" seats and adding TEL with much wringing of hands and gnashing of teeth. "Regular" (non-gearhead) folks just started using unleaded premium and not worrying about it...and when I started tearing down those engines in the 90's I rarely found seat erosion, etc. unless the engine was really used hard.

I agree with cdowns - don't go looking for trouble
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Old 07-14-2007, 10:23 AM   #12
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Re: Can I run unleaded gas

If you look at GM literature from 1971 and 1972, you'll notice they say you can run your vehicle on "low lead" gasoline. So if your heads are 1971 or later you're ok.

When I bought my truck in March of 1994, it spent its previous years running around the state of Wyoming where they still had leaded regular available. The PO put together a junk yard special engine. The block was a 4-bolt truck 350 out of a 1978 truck. The heads were much older - I never ran the numbers.

Anyways back here in Minnesota the Al Gore believers already did away with all the lead pumps so I ran it on unleadeed. In November, passing a truck on the way up deer hunting, it started barking through the carb. When I finally pulled a head because of low compression, the valves on #6 and #8 were "sucked" up farther than the other valves. I can only assume this was older, non-hardened valve seats that got hammered away with the lack of lead.

I guess what I would do is forget the additives. Buy unleaded. If they heads can't take it you'll know soon enough. If that happens, just put $125/head in them (hardended seats and bronze guides) and put them back on.
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