i got a 350 carbeurated block sitting here in front of me, and a set of 327 heads....thinkin about cleanin em up, boring them out and bolting them to this thing and dropping it into a 2nd gen i got, or possibly my buddy's TA....would i get much more power from the 327 heads?

 

depends on the size of the combustion chambers. larger chambers have lower compression ratios, so they make less power.

 

Yeah... There are a number of different 327 heads, post a part#.
In some cases they won't have the right mounting holes for thirdgen accessories too.

 

It depends on what 327 they came from... they ranged from 200hp, 2bbl POS engines in cars that were for getting Grandma to church and ran on basically anything you put in the gas tank.... to 375hp fuelie Corvette motors that would run on nothing less than 104 octane.

So what casting number ya got?

 

there were no 375 hp 327s and the l79 would run on less than 104 fuel. how do you propose to bore out the heads? i'd consider a few things, like the 30 years they've been around. valve seats made before unleaded fuel was all you could find. i'd also look for bolt holes i nthe ends of the ehads for acessories.

 

thanks for the input so far guys, i appreciate it. Will get the casting numbers on the heads tonight (they're sitting at my best friend's house) but from what I was told they were yanked out of an L79 Chevelle....so yeah, we are talking about 40 year old heads, hahah...(although the 350 block's from a '69 camaro and she purrs like a champ after we cleaned her up nicely)

 

Well considering that probably less than 1% of all L79 Chevelles still have the heads on them that came on them, that's anything but a certain means of identification.

Post the casting number. It's the only thing that will truly tell the tale.

If they don't have the accessory bolt holes in the ends, then that's the explanation of how you came to have them just laying around, probably for real cheeep..... they don't fit anything that's been made since about 1970. More accurately, they don't fit the accessories in any car, since around 70.

 

Not that it really matters to this thread... but yea, there was... it was one of the FI motors for the '65 Corvette.

 

aiight, these are L79 heads (apparently originally off a chevelle, but they've been around the block and back on other cars...) if i had my digital camera i'd post pics of the casting numbers. Ran em thru the computer a few times...

By the accesory bolt holes, we mean the extra set of holes on either side, right? because the way we have them sitting, it looks like it'll mount perfectly to this 350, granted its a '69 350....im just wondering if there would be a benefit to mounting these heads over 350 heads if i bored em over the same way...

 

If they're really L79 heads, they won't have the accessory bolt holes in the ends, and you won't be able to put accessories (just minor details, like an alternator for example) on them.

The year of the block doesn't matter in this regard.

If you don't know the numbers, then how do you know they're L79 heads?

Don't bother with pics of the casting numbers; just post the numbers themselves.

Here's the holes you need. If the heads don't have these, they are no good for one of these cars.

 

ok i stand corrected i did find a referance to a 375 hp mechanical fi 327 in 65. i also for another referance saying it didn't produce near that and the l79 was the more powerful engine, and cheaper.

 

The L84 was 375 HP in 1964-65.

 

327 Cylinder Heads

 

327ci (375hp) Corvette

 

yeah doesnt have those....bolt holes....I see what yer saying completely...

::shot down::

 

Still, if you're going to use it in a 2nd gen, and if the only belt driven accessories are PS pump and an alt, then it's not an impossibility.
What about the casting#?
Your original Q was, would you get more power out of those heads.
To tell you that, we'd need to know what heads you originally had and what heads you want to replace them with. Casting #s!! Please

 

working on gettin em, heehee (been busy with work/family) the engine i'd consider plopping it onto would be out of a 1978 camaro Z-28 350 4barrel....not gonna use the '69 engine now. Whatever came stock on that engine is what's on it right now...(Im sure the stock '78 camaro heads are close to doggy-poo, as most of the 2nd gen stock engine components are...

 

Sounds to me like you're officially mesmerized by the "L79" sucker line, regardless of whether it's been verified or not; and you aren't interested in even entertaining the possibility of that bubble being burst. I don't think you understand yet, how critical it is to properly identify the parts you're looking at, before you spend money or turn bolts.

There's no difference in any practical terms between an engine built with a block that was last found in a 78 Z28, and a block from a 69 model engine, that you can trace to the block. It all depends on what pistons somebody put in them, what hardware they used, the care taken in machine work and prep, etc. It has nothing to do with the year the block was cast, or the sheet metal it was last observed to be wrapped in. There's certainly no difference in whether those heads will fit on it.

The 2nd gen bracket system is the same as the early 3rd gen (or late 1st gen for that matter); an alternator from that vehicle won't fit on those heads any better than one from any other vehicle with the 69-up system that requires the bolt holes in the heads. There's no magic in the 2nd gen sheet metal that will convince an alternator to stay put without hardware. No bolt holes = no alternator. That's one of the reasons why it's so easy to pick up those old heads so cheap these days. They're basically useless on almost any car that anybody actually still has.

Since you're evidently just determined to use these heads on something, anything, no matter what they really are, there's not alot any of us here can do to help you out. Do what you're going to do, and the results will be whatever they'll be, good or bad. I hope it turns out good for you, and of course it might; but who knows. But if you seriously want help and advice, and not just for everybody here to jump up and down and agree with you that those heads will work miracles like take a 180 HP 70s smogger pig and turn it into a 500 HP stomper with 34 easy bolt tightenings, then get the casting numbers and post them. Take a deep breath, dive off into some reality, and find out what the heads REALLY are. Then you'll have something that there's some factual information around, that has meaning.

Enjoy!!

 

I'm about to buy an '84 Monte with a 355 and the 327 double hump heads. Are there different types of double hump heads or are they all pretty decent?

 

Yes there are more than 1 type of double hump heads. The easiest way to tell what they are exactly is to get the casting numbers and look them up