Can you help me identify my motor?

[parobellum]

New to me 1969 C10 - originally a 396 w/AC - currently has a big block and vintage air system and runs great - I am very happy. Motor ID has been odd as I was told it is a non-original motor.

I managed to find the intake manifold number (see below) 3931067 which i decoded as

3931067 1969 396 325 L-35

I also found the date code E6|9 I believe (pic below) so May 1969?

I finally found the block casting # after an embarrassingly long time and even buying an endoscope (mostly because it looked cool. And it is.)

To me it looks like 3855961 P which decodes as 1966-67 396 325, 360, 2 bolt

I am assuming based on the manifold its an L35 (396/325).

While I think I am correctly assuming it was a swap, I cannot find the vin number despite watching youtube videos, looking at every pic on the web . Can anyone highlight my stupidity and help me out?

[parobellum]

Sorry for the huge pictures. Also - the block casting decodes as a 66-67 but the date seems to be 69? Maybe some clarity on that? thanks

[71CHEVYSHORTBED402]

You might compare the truck build date to your intake manifold date. E6/9 is May 6, 1969. If that date precedes the truck build then it may be original to the truck. Assuming the date code on your intake reads as you say, then mine reads a pinch differently as "D22 71", for April 22, 1971.

Your block may have a date code too. Mine is located just above the transmission (see pic.) Mine reads like my intake, only 9 days earlier.

Trucks didn't have any portion of the VIN on their blocks. I can't speak for passenger cars, maybe some did.

Regardless your engine may not be a replacement. You need to see a date code to narrow it down. For what it's worth, near everything on my truck with a date code precedes the truck build date by approx. one month.

3855961 396 65-67 Passenger 325 HP,2 bolt mains
3855961 427 66 Corvette 390,425 HP,2 & 4 bolt mains
3855961 396 66 Chevelle 325,360,375 HP
3855961 396 68-69 Truck Light Duty

https://macc.chevelles.net/bbcast.htm


Concerning your pictures, it's best to upload images using their paper clip under "Go Advanced". They look like this and won't disappear.

[kwmech]

Pics are so huge on my monitor it looks like I need a 1'' socket for the hose clamp

[71CHEVYSHORTBED402]

Originally Posted by kwmech

Pics are so huge on my monitor it looks like I need a 1'' socket for the hose clamp

[special-K]

I couldn't deal with the pictures. Just scrolled down here to reply. What we need to help you ID your engine is the suffix code. Then you can look that up on www.nastyz.com

[parobellum]

Again - apologies for pics. So where is the suffix code/engine code located? I see its supposed to be "Big Block Chevy: Machined pad in front of the passenger side cylinder head or above timing chain cover." but where is it in relation to the block code I found?

[71CHEVYSHORTBED402]

Originally Posted by special-K

I couldn't deal with the pictures. Just scrolled down here to reply. What we need to help you ID your engine is the suffix code. Then you can look that up on www.nastyz.com

What's an example of suffix code Tim, and where do you find it?

[geezer#99]

Look here for suffix code location

https://www.mortec.com/locatpg2.htm

[fourspeedwagon]

There’s a flat pad on the front, passenger side. About an inch by 3 or so wide. It’s under the hoses that are by the bracket holding the AC compressor on. It’s level with the surface the head is mounted to. The numbers (and a couple letters) will be stamped into it rather than raised/cast into the block. Find those and post them. We’ll be able to help easily id it.

[71CHEVYSHORTBED402]

Originally Posted by fourspeedwagon

There’s a flat pad on the front, passenger side. About an inch by 3 or so wide. It’s under the hoses that are by the bracket holding the AC compressor on. It’s level with the surface the head is mounted to. The numbers (and a couple letters) will be stamped into it rather than raised/cast into the block. Find those and post them. We’ll be able to help easily id it.

Oh yeah, I forgot about that one. Thanks to you guys I had this written down:
T0426TKB. T stands for Tonawanda plant, and 0426 is for April 26th. The TKB suffix code means 71-72 truck L47, with a 400 transmission.

Okay I give, how come the back of my block reads April 13, 71 and my suffix reads April 26, 71 I'd look but she's well protected right now.

[parobellum]

So I know I am being dense and I apologize, but I think I have the pad you mention and see nothing on it, cleaned it, brushed wiped, still nothing. Also tried the small pad at the center above timing cover, blank. Am I getting the wrong location?

[geezer#99]

If there’s nothing there then that means your block was decked and the info was removed.
Decking cleans up the head surface for a rebuild.

[parobellum]

Ah - so maybe that ends the search for further identification?

[fourspeedwagon]

Try a little sandpaper. They aren’t super big like the cast in digits. Otherwise, when an engine gets rebuilt, sometimes they need to machine the surface where the head mates and if so those markings will get shaved off.

[geezer#99]

Originally Posted by 71CHEVYSHORTBED402

Oh yeah, I forgot about that one. Thanks to you guys I had this written down:
T0426TKB. T stands for Tonawanda plant, and 0426 is for April 26th. The TKB suffix code means 71-72 truck L47, with a 400 transmission.

Okay I give, how come the back of my block reads April 13, 71 and my suffix reads April 26, 71 I'd look but she's well protected right now.

That’s because most blocks were cast a couple weeks before being used Tony. Some weren’t used until 3 or 4 months after casting.

[special-K]

Originally Posted by 71CHEVYSHORTBED402

Oh yeah, I forgot about that one. Thanks to you guys I had this written down:
T0426TKB. T stands for Tonawanda plant, and 0426 is for April 26th. The TKB suffix code means 71-72 truck L47, with a 400 transmission.

Okay I give, how come the back of my block reads April 13, 71 and my suffix reads April 26, 71 I'd look but she's well protected right now.

That's the difference between when the block was cast and when the engine was assembled.

[71CHEVYSHORTBED402]

Originally Posted by special-K

That's the difference between when the block was cast and when the engine was assembled.

Wow. Nice one Tim, I don't figure too many know that.

[BigBird05]

When the block is cast at the foundery you get a cast date, time stamp and shift designation. They can sit for awhile till they are shipped to the engine plant. Chevy had several back in the 60's and 70's. From the engine plant they are shipped to the different assembly plants where they get the application stamp just pryer to being installed in the vehicle.

[parobellum]

Found this on the bottom - HIPERF PASS and then maybe a K and a 13?

I also found an A on the manifold.





I know the hiperf pass does not mean much, if the K 13 is a date code seems to be missing the year

[parobellum]

Anyone know if this is the date code? Seems like it should be but I am wondering where the year is.

[GASoline71]

Super rare High Performance block!









j/k, they pretty much all had that cast into them.

Gary

[parobellum]

I will admit to a small moment before I saw that online - but does anyone have an idea where the year marking would be?

[geezer#99]

As it says in the Mortec link I posted, it might be by the freeze plugs.

[parobellum]

That link is great - i was more wondering why I can see K 13 but no year date (per my pic above)