i ran across a set of heads that had a marking on the ends that I didn't recognize. It is the shape of a pyramid sort of like



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l l


Again it's a raised stamp similar to the double hump. The engine numbers ran to be a 350 used between 69-72 Z28s. I thought a stock 350 was a stock 350 till later in the 70's. Any chance any of you hot rod guys or old school mechanics recognize this symbol and if so do you have the numbers valve size/combustion chambers for them? The head look to be in decent shape, appear to have been ported and probably worth a rebuild.

 

That was a very common casting marking on old heads. Mostly meaningless. About all you can tell from that, is that it's not double-humps.... because the mark is something other than a double hump.

Get the casting number. All else is just a bunch of vague guessing.

 

I'll try to get the numbers in a couple days. Generally speaking what will that number tell me. No chance of this block being a LT-1 is there? That would be an awesome find. 360hp from the factory.

 

Chances are somewhere between Slim and None, and Slim is on his way out of town.

Regardless, blocks don't make HP; heads and cams do.

And as stated, those aren't double-humps, so they're not from a LT1, so it doesn't matter if the block used to be or not. It's not a LT1.

Don't worry about any of that. It's all monkey-spank. Only thing that matters, is what it is.

Get the head casting # (or #s).

 

The LT1 used the same block as a whole lot of less-remarkable engines.

 

blue do you mean like this /\_/\_/\ ?

 

kinda looks like the symbol on a set of heads I have, the casting #'s are 3947041 on mine.. not sure if its the same head though.. and i'm sure if the ones I have are good heads or not.. can you pull a valve cover and look?

 

this thread is worthless without casting numbers

 

nope it's like
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The head number is 8795898, searching found nothing for this number, it's stamped under the rocker arms. If I change all the 8's to 3's it comes up as 327 heads, but unless someone's playing a good joke on my eyes, they are 8's I used blue wolf and a rag and scraped down to bare metal to make sure I got the numbers right, anybody got anything?????????????

1968 3970010 327 - - 2 A
1969-79 3970010 350 185 370 2 or 4 car, truck, Vette


This is the block number's result. How could you tell the difference between the 350 and 327?? the 185 is low hp rating and 370 max. 2 or 4 bolt mains, I'm a dumbazz I just answered my own question sort of, pull the pan and if it has 4 it's deffinatley a 350, if not a 4 bolt main how can I distinguish then?

If it turns out to be a 327, are these a worthy performance engine? This was a tourqe monster. With better gears and some subframe connectors it would have been sweet. I was in the car and the guy outran a L98 vette. The guys in the vette stopped and talked to us and he could not believe it. We thought he was sand bagging but he said when we shifted into 2nd he couldn't keep up at all. It had holley street dominator high rise , single plane aluminum intake, 850 double pumper holley and all accell electronics bone stock 350TH and stock converter. A 3" true dual 40 series flowmaster exhaust with no cats. If this is a 327, there has to be some major machine work done.

 

The number of main bolts has nothing to do with the displacement. The only thing it affects is how many bolts you have to use to put it back together.

The blocks are the same for a 327, a 350, or even a 302 for that matter. It's the crank that determines the displacement.

 

so how could i determine 350/327??

If a 327, would that be a rare find? I mean is there still alot of em around?

 

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Looks to me like the old "Power-Pack" heads from the late 50s through about 1967-68 (before bolt holes for accessories).

The "hot" heads before the double-humps came along in '61-'62. Most I've seen were on two-barrel vehicles in the early 1960s.


jms

 

3795896....63-65...283......60cc chamber
3795896....62-64...327......60cc chamber

Nothing-special kind of old heads. Maybe decent for their day but not even the best of their time; note that ALL 63-65 283s were 2-barrels. NOT the "Power Pack" heads IIRC.

They won't have accessory bolt holes, which means that they won't work in a car with any of the accessory (alternator, power steering, etc) systems that have been in use since about 1969.

Only difference between a 327 and a 350 is the crank and pistons. Bore is the same, rods are the same. The crank has less stroke in a 327, and the pistons are taller because the wrist pin is lower.

A 327 is not a "torque monster" any more than a 305 is. That's laughable.

A 350 will beat a 327 built out of the same parts (heads, cam, compression), EVERY TIME. Hands down, no other outcome possible, no further questions asked. That's why we all quit building 327s when 350s started becoming widely available to us in the mid 70s. Take the same parts and the same money, put it into a 327, LOSE. Gets REAL OLD, REAL QUICK.

No being a 327 does not automatically make it a "worthy performance engine"; any more than being a 350 does. There are some SERIOUSLY CRAPPY examples of both in the world. The 010 block is possibly the single most common 4" bore casting, so there's NO TELLING what's really inside it. Probably no more than a couple of percent of them still are what they left the factory as.

Sounds like the guy in the Vette that you tell the story about, did all the typical Vette loser things. Un-bolted and re-bolted all those nice big shiny things that sit up there on top, so that all the 8-yr-old kids in parking lots can oooh and aaaah over the bling. It was probably a 8¼:1 L48 short block underneath all that. That's NOT how you make a car go fast. I wouldn't attach too much significance to that. You also don't tell us what kind of car this was in; if it was something small and light, it can be pretty tough for a 3600 lb Vette to compete.

All in all, doesn't sound like anything worth pursuing, IF YOU'RE BUILDING ONE OF THESE CARS. Nice romantic old-school campfire stories only go just so far in producing enjoyment. Practical concerns, like getting fuel and bolting up alternators and stuff like that, have a way of re-ordering priorities.

 

It has been awhile since I've seen original 283s and I was pretty sure there were 4-barrel versions in the mid-60s, so I pulled out a couple of old Chiltons (the big thick versions from my youth) and there were indeed 4-barrel 283s listed:

220 horse version in 1964 (195 hp with 2 barrel) and again in 1966 (don't know why not listed for '65 in Chiltons) for the "small" cars and just '66 for the "big" cars.

Did a little more searching in my collection and found the L77 RPO code for the 4-barrel 283 in '64 and '65 Chevelle SS, '65 & '66 Impala SS, as well as the '65 and '66 Chevy II Nova SS (this info from Chevy Super Sports 1961-1976 by Terry V. Boyce-printed 1981).

The term "Power Pack" came about in the tri-five Chevies of the mid-'50s as an optional power improvement over the basic small-block of that era.

In my opinion, the heads with the markings (the thread starter mentions) are worthless-except to someone wanting to restore a project to absolute numbers matching.

As a somewhat amusing note, I've seen double-hump head markings ground down to the "power-pack" markings (on just the forward facing side) in order to get by strict rules on both oval and drag cars.

jms

 

It was a 79z the motor was in, not a light car. The vette was factory as far as the bolt ons(no xray vision to see internals), no bling at all, just really well maintained. I think late 80's at best, before the oval taillights, lmfao the "barbie" corvette. It wasn't a pushover car. The guy complimented him that he never would have thought he would lose.

I'm assuming it's a 350 block with sucky heads. It was very Tourqey. Of course there is no telling, so I think I'll pull the heads and measure the bore, drop the pan and see if it's 2 or 4 bolt. Anything else I should take note of while I'm in there?

Should the crank have a number on it as well? If so where would it be located?

The engine had a healthy cam in it although I have no clue what the specs were. I know there is no way of identifing a cam that easily. I was thinking whoever built the engine may have purchased one of the holley performance kit because of the intake/carb combo? If that is a possibility, how could I find out?


This engine ran strong. It started puffing smoke and he pulled it to minimize damage to cylinder walls. It was rumoured to him that it had been bored .030 or .040 over, wasn't sure and didn't want to chance going to thin of walls. He was going to rebuild but never did so it's just in his garage. I'm just trying to trace the history of it and find out exactly what it started life as, what was done and what it is now. Every hotrod has a history I don't care what anybody says. If not we all wouldn't be part of this culture. Camaro's have a heritage, no pun intended, thorough bred blue bloods.


this is off topic but I saw a 75 chevelle the other day (the really big ugly ones, ugly to me at least) On the emissions label where it states engine size was 350/400?? To my knowledge I've never seen one state the transmission size along with engine (400TH). I don't know of gm stating optional engines on these labels nor do I know of a gm 350 modified 400. So what the hell does that mean?

 

That label probably applied to both the 350ci engine and the 400ci engine. Both were available in those cars, and making one label that applies for two different engines is cheaper than making two different labels.

 

The '67 impala I had with a 327 4bbl had that head casting mark on them. (I think it was rated at 250hp) It had the 1.72 intake valves and the small chamber (58cc - 62cc) to go with the 327" displacement. These heads bolted onto a early stock 350 would bump the compression into the premium leaded gas range and make the "torque monster" you describe with the higher compression ratio, but with the small valves it wouldn't breathe above 5K. (this was a common $0 parts swap back in the day)
The 275 hp 327 had 64cc 1.94 camel hump heads on them and those are the heads that are on my 350.
Those single peak heads are probably useless because they lack the accessory bolt holes and have the small valves.
(I guess my age ain't a secret anymore )

 

I had a '68 Impala 327 4-bbl with those same heads... I paid $25 for it, in about 76 or 77. You can about guess what a POS it must have been.

 

so keep the block (if 350) and trash the heads. Unless some guy building the next barret jackson fortune prize is needing an all numbers car lmfao.

Yep scrap iron they go.

 

anybody know where that crank number is located exactly?

A free useable 350 block would be a nice gift. Never know when I may need that.