Hey everyone, I bought a 1984 Firebird(originally 2.8 V6) with a "355" in it. The guy bought it off his grandfather and sold it to me for 1500 telling me it was a 355. I went on to look at the heads and found out they are early 327 heads with the casting number of 3872461 and have the camel humps on each one. I checked the back of the engine and it had 25GM 3970010 with a weird tear drop like symbol and the letters NDT surrounding it(so 4.00 bore 2 or 4 bolt main block). Now whats really creepy, my intake manifold has the casting number of 3832472. I couldn't find it anywhere and then I decided to google it. What came up was a 302 intake manifold from a 69' DZ Yenko Camaro. The picture totally matched my Intake manifold casting number and all. What is going on here?? Do I have a rare desirable engine? The suffix code on the front of the block is completely useless(almost illegible) the best I could make of it was CEB 1331 80.... but that can't be right. The engine runs VERY strong, has 50-65 PSI oil pressure at 700 rpm on start up. On throttle it goes to a good 80-85. The heads have absolutely no sludge on them. Someone please help me!

 

The block could be over 40 years old , it is highly unlikely it has any original parts on it so it is just another small block Chevy block
What you most likely have is a collection of odd SBC parts thrown together by somebody just like members on here do
when they build a bitsa engine from " real " deals they got.

Why not ?
You just admitted yourself the 302 had DZ stamped there.
That block casting # was made for at least 10 years for mainly truck and pass car engines , not just early HiPo

 

Just because someone said that in their eBay adv ...........
GM mix n matched , reused a lot of parts over the years for different combos

 

That can be right because the CEB suffix doesn't exist and the CED/CFD suffix(looks similar) is an LG4 305. Which this is definitely not. Also! Why when I go to three site with Chevy intake manifold casting numbers does my casting number not show up? Come on guys... I couldn't find it anywhere. Until I straight up googled it, nothing came up but that. I can't find any info on that number. Strange? There is no mistaking what is on that manifold. I read it properly.

 

The listings you will find online are not complete , private people have put them up from their own research; they are not from GM .
Most have a disclaimer like
" This list of codes is a summarization, it is not complete nor all inclusive."

So you have a manifold that was fitted a 302; has no bearing on what the engine is now ( or was) The 010 block casting tells you that it is a 350 , the only info that is useful

Read this for better understanding how Chevy suffix codes work
http://www.nastyz28.com/chevy-engine-code-stampings.php

 

The suffix code is altogether meaningless at this point.

All it tells you, IF THAT, is what engine THE BLOCK was a part of when new. It tells you NOTHING WHATSOEVER about what THE ENGINE is now.

You've already told us that you've got a 010 (69-up) block, heads from the mid 60s, and an intake from the late 60s. You don't have "A MOTOR", you have A BUNCH OF PARTS assembled into one. Therefore what you have now IN NO WAY WHATSOEVER resembles whatever that stamping code refers to. It might turn out to be a 76 Impala 350 2-bbl; might turn out to be a 70½ "X/28" "LT-1"; might turn out to be a 78 phone company van; could be ANYTHING. Doesn't matter any more. Instead of any of that, it's whatever somebody turned it into when they "rebuilt" it.

Basically, it's the sum of its parts. No more, no less.

It's not "rare", "valuable", or any of that. Some of the parts might be, individually; but being bolted to yerbasic "mutt" engine like that, it's kinda irrelevant. Anybody can grab up ANY intake and bolt it to ANY block and/or heads, but that doesn't somehow endow the motor with some kind of special magic.

The "engine" has no particular value as it sits, beyond what any other such motor would have. If it runs good, doesn't leak, etc. etc. etc. and is therefore otherwise satisfactory, then enjoy it for WHAT IT DOES FOR YOU, and leave a bunch of "rare" out of it, because it's NOT.

No stock intake from the 60s runs ANYWHERE NEAR as good as a modern one. Especially not with modern fuel, modern competition (which I can ASSURE you, has advanced substantially in the last 45 yrs), modern expectations, and so forth. The only type of person to whom it would have "value" is someone trying to replicate one of those old motors for a "numbers matching" type of build. It won't win races: that is, if you took it off and WITH NO OTHER CHANGES just put a GOOD MODERN one (Perf RPM for example) in its place, you'd get more power.

But as said, enjoy it for WHAT IT IS, rather than make up fantasies about something it's NOT and try to convince yourself that they're true. If it runs good and you like it, then just enjoy it.