2007-12-23 08:52:12 · 12 answers · asked by jamesr437 1 in Cars & Transportation ➔ Car Makes ➔ Chevrolet
Since leaded gas is illegal to sell that isn't an option. Running unleaded will cause the valves to run hot and die sooner than they would have with leaded gas. However if that engine was rebuilt since the mid eighties it probably had hardened valve seats installed and there wouldn't be a problem with unleaded gas. I run it in my old Mustangs from the 60's without a problem but they have all had hardened valve seats installed.
2007-12-23 09:11:50 · answer #1 · answered by mustanger 7 · 3⤊ 0⤋
leaded if it has the original valves. unleaded requires harden valves. since it very hard to get leaded fuel, use a lead substitute. i have been for years without any problems. once in awhile just unleaded is ok, but not a steady diet
2007-12-23 14:42:46 · answer #2 · answered by racerwesu 4 · 0⤊ 0⤋
They were designed to run on leaded but you'll have to run unleaded. If you have not had some one re-do the heads and have hardened seats installed, you will find that after some time you will get valve seat erosion and quite possibly damage to the heads and valves in the long run.
2007-12-23 10:30:20 · answer #3 · answered by G T 6 · 0⤊ 0⤋
Only unleaded is available. Leaded gasoline was phased out way before I was born in 81. I would go for a higher octane rating of unleaded with an older vehicle. But without knowing what engine and compression ratio it's hard to say.
Check this article out from Wikipedia
http://en.wikipedia.org/wiki/Gasoline
2007-12-23 09:00:19 · answer #4 · answered by Jay W 2 · 0⤊ 1⤋
First of all in 1969 all cars ran on leaded gas......the days before catalytic converters.....next, has that car had an engine rebuild??? If so, did they use case hardened valve seats? If they did you can use unleaded gas with no problems. if not add a bottle of lead additive to your gas.....personally for best performance I would use 93 octane fuel in that car....in my 66 GTO I use 93 octane and it runs like a top.
2007-12-23 09:20:51 · answer #5 · answered by Anonymous · 1⤊ 0⤋
With today's octane ratings and gasoline refining, unleaded gas will be fine. I have a fully restored 1966 Corvette and it runs fine on unleaded fuel.
2007-12-26 12:00:30 · answer #6 · answered by Franky1 1 · 0⤊ 0⤋
Leaded, but I never put it in my old cars. Nothing ever happened to me... I still live with my mom. ;)
Mustanger is right, the lead would protect the valves. That being said has anybody ever SEEN a valve seat pulverized due to lack of lead... Niether have I and I've owned a 76 gremlin with a 71 V8 in it, a 72 dart, an 84 dodge van with a 71 slant six, and I currently own a 51 buick, and like I said nothing ever happened to me. I think if my valves ever crap out I will have those hardened seats put in at my local machine shop. Untill then you may as well tell me I need elephant urine in my gas, but I'm not paying extra for it.
And I was kidding, I don't live with my mom.
2007-12-23 08:58:01 · answer #7 · answered by BFH 6 · 0⤊ 2⤋
leaded,which is not available,but they make a additive to compensate for the lead, long term use of unleaded will degrade the valve seats
2007-12-23 09:12:42 · answer #8 · answered by rocky w 3 · 1⤊ 0⤋
They were designed for leaded gas. But now you have no choice but to use unleaded gas (unless you go to local small airport and buy AV-GAS - aviation gas / leaded fuel).
To compensate a little, use motorcyle engine oil. They have more additive (ZDDP) for the bearing.
Good Luck
2007-12-23 09:06:04 · answer #9 · answered by Lover not a Fighter 7 · 1⤊ 1⤋
Leaded unless the valve seats have been changed to the Stellite ones.
2007-12-23 09:00:40 · answer #10 · answered by Anonymous · 1⤊ 0⤋