Gary's '66

I don't race my car either (original motor, trans and rear end, btw) HOWEVER, every now and then I will run it through the gears close to 200-300 under red lining it, and an occasional rolling burn out. What the hell, IMO it's not much fun having a sports car unless you "run it through it's paces" so to speak from time to time. It's what they were meant to be used for in the first place.

ricks327

Donny,
Yours runs more than "just fine".
Rick

skyjerm

I researched this online (so it must be true : any 327 is basically a 327 with different cams, carb, intake, etc. Meaning, the difference between an L-79 and an L-2x or 3x is what it puts in and not what it puts out.
I'm not inclined to agree with that based on pure physics, but I can find no facts to dispute it.

Anyway, to your point (what gas to put in it), the most popular guidance is to put the cheapest octane that won't knock. For me (327/350hp), that's full premium (91-93 octane, depending) gas in California, although I had some luck with Super (89 octane) when I was feeling more experimental. If I lived near a drag strip, I'd put in 105 octane and try not to blow my heads off. Seriously, too much octane is not a good thing.

hockystik

Thanks again for everyones response. Not an issue anymore. Over the weekend, I found basically the same car, but with the 327/300 and loaded with options. I bought that car. Only drawback is that it’s an automatic, but I can deal with not shifting a nice car. Now that I own one, I’m sure I’ll have more questions in the future.
Mark

BB767

Congratulations Mark. While the 327/300 doesn't have the halo around it like the L-79 does, I'm sure you'll find in real world street use it will be an easy engine to live with, especially if you've got a power glide.
Now post pictures of your new car please!!

Thomas

Gary's '66

Congrats Mark, it sounds more like the car for you going by the way you described your driving habits. Good luck and POST PICS ASAP!

Basicman

OK, I can give you the real skinny from my own experience. I have a 65 327/350 that is still a factory sealed engine. I have had this car since 1975. I use it and I mean use it. Great Lake tours, weekend get aways exceeding 1000 miles,Smokey mountain tours, everyday use and just all around useful car. Still has points. I run midgrade. When I first had to run unleaded back in the 70's, it spark knocked, but as the years went by and the old carbon residue cleaned up, it started to run just fine on unleaded and I have the original heads without hardened valve seats. Also, spark plug life improved significantly, probably by a factor of 3 since I still have the same plugs that I installed over 30,000 miles ago and they look fine. Great engine.

ditchdigger650

I bought my L-79 in April of 1991 and have run 91 octane in it since day one, never had a problem. I've had several 327's through the years and this to me is the best running small block engine GM ever produced.

Basicman

I posted a thread recently on hardened valve seats and the fact that I was working in the auto industry back in the late 60's and early 70's. One of my first projects when I joined Chrysler was to run a bunch of tests using unleaded fuel. Bottom line was we could sink valves on the engine dynomometer but rarely on road tested vehicles. We ran severe cycles to assure we were OK. Also, if the engine saw any leaded fuel and I mean a small amount like the factory fill, the valve seat life was significantly increased by multiples. So, all 327 engines saw leaded fuel, therefore, unless you regrind the valve seats, they should last a long time.

morly1963

I had a high HP engine in my 1970 Vette a few years back and put a can of "Octane Boost" in every fill-up. After getting tired of that I just ran the gas with-out the booster and couldn't feel a difference.
The engine was fine.

Basicman

My experience and I have 40 years in the auto industry and a lot of it in fuels and lubes is that those octane boosters and upper valve lubrication products don't do much if anything. If one can get a gallon of aviation gas with real TEL, then that will do more than anything for the valves. Very little required. A little TEL goes a long ways and I suspect you don't even need that. When we ran the tests, we measured valve stem heights every 3000 miles and that is how we determined ef the valves were sinking into the seats, but we never saw an engine failure as I recall. The industry went to induction hardened valve seats mostly because of heavy duty operation like trucks and heavy trailer tow. In summary, I never saw a disabling engine failure due to running unleaded fuel in vehicles with non hardened valve seats. Hope this helps.

ricks327

Basicman,
Did you work the dyno at the Auburn Hills, Mi. location?
Rick

emdoller

Mine too runs fine on 91 octane.

As far as 350HP vs 300HP, I don't want to get into the benefit of 50 extra HP but I will say that there's nothing like the distinct sound of an L79. I have both motors and will take the L79 in a NY second.

65 vette dude

I have a bone stock 65 L79, and I have my total timing at 34º. I run 93 octane, and I have never had any detonation.

jimgessner

Bought a 65 CHENILLE SS L-79 new. Owned three L-79 Corvettes over the years. My 66 convertible had air conditioning. These were the best running Chevrolet cars I ever owned, and I had over 100 Chevrolet cars in my life. I love Rochester fuel injection and solid lifters.....and the old 327/300hp engines. But L-79 were the best bang for the $$$. In 1965 where could you find this much fun for $107.60?

Jeffthunbird

I'm resurrecting this old thread. I bought a '67 coupe with matching number engine and I'm told it is the 350 HP. It has a sticker saying this on the air cleaner lid but I don't think those were factory. How can I confirm which small HP rating I have?
Thanks

Easy Rhino

Look at the engine stamping on the passenger side of the block surface just forward of the head.

If the engine is original, it should have two alphanumeric codes. The one on the left will be a partial VIN and should match the last six of your car's VIN.

The one on the left should start with the letter "F" and be followed with a date code and a two letter suffix. That suffix tells what the engine is.

On the surface of it your engine appears that it could possibly be original, valve cover paint excepted.

You appear to have the 461 aluminum intake manifold, so if original it is either the L79 (350 HP hydraulic lifters) or L76 (365 HP solid lifters).

Correction: Reading is fundamental - yours is a '67, it cannot have the L76, so it almost sure to be the L79, a very well-thought of 327 engine.

Post the codes here and I'll break out the "Lime book" and interpret.

Frankie the Fink

On the front of the block at the PS head there should be a pad with a number on it...the letter suffix at the end should tell the engine type IF it hasn't been altered (which does happen unfortunately)...

Nowhere Man

There's is no need to have this thread come back to life. Just make a new one.

Butto answer your question yes 67 cars used a air cleaner decal showing cubic inch and horsepower rating. But it's a poor way of determing what your engine is. As they have been selling them for years cheap. What you can look for is the engine stamp pad. That is located on the passinger side of the block on the front. If you look down at the end of the valve cover you will find it. If it's covered in paint DO NOT sand the paint of. Use lacquer thinner and remove. Then take a good close up picture. From the looks of the intake you have a L79 327/350

Jeffthunbird

Thanks a lot for the info. The number matches the VIN which I knew but it also displays the HT which is the L-79 4-speed which is correct.