[steve]

found a mark on the oil pan rail...will it tell me who built it ? is there some sort of cryptology with the marks ???

[1971WARBIRD]

would have to post pictures.a set of heads i bought had JBP on them,when i called and told them and gave them the number that followed they had all the info on the heads.you might get lucky also.

[steve]

the only one i have found yet....

[Keith Seymore]

Steve -

I am not sure I understand the original question....

Are you asking if assemblers in the Pontiac engine plant somehow left marks to indicate which engines they built?

Or are you asking if an aftermarket engine builder left a signifying mark in there?

To my knowledge, the production operators did not mark engines they built, although you might see inspection verfications on some parts (ie, torque marks, paint daub indication a completed inspection, etc). The inspection marks often are assigned to an individual, so if you see a punch on a repair ticket that is a clover, or a heart, etc, you could theoretically trace it back to a particular person. It would be virtually impossible to do 40 years after the fact.

I have a fellow Pontiac enthusiast friend who used to work on the V8 engine line in Flint (building Chevy small blocks). He likes to tell people "...I've built more engines than you have ever seen...".

K

[steve]

this is an aftermarket engine builders mark...right ? an "M" or "W"....

i also see several marks on the deck and intake flange of my heads, on the 400.

[rustedgoat]

I know salvage yards used to mark their engines somewhere with a stamp if they warrentied the core. I'm sure some rebuilder do the same.

[Brian Baker]

Someone's marks that rebuilt the engine sometime after it left the factory. As to who it is, who knows? Now if there were a JB or JBP on there, it would likely be Butler, but a M or W? Who knows.

[firebirdcrazy1959]

Its a factory mark,i have blocks that are stamped with different letters.On the deck,on the pan rail,etc.

[johnta1]

I've seen a few of them next to the main caps. I figured it was for the assembler to pick the right bearings for fit. My 70 WS block has them and my SD had them I believe.

[FBNRacing]

Originally Posted by Brian Baker

Now if there were a JB or JBP on there, it would likely be Butler, but a M or W? Who knows.

That would be mark williams, mark williams built this motor.


Rex

[goatman65]

factory stamping.I noticed the same thing on mine a couple days ago.Dont remember what letter it was,I have to look.It also has a letter on the deck surface,I think it is a capital 'A'.I doubt these markings are of any use.

[ho428]

I have a RA-V block that the casting numbers do not exist in any known data base. But on the deck is an odd looking XP hand stamp. I was told that meant experimental as it was a supplied to a factory supported racer. Not sure if that's true, but that's what I was told.

Also, be wary if you have a rare block. Some engine builders will stamp their number on it without telling you. I had that happen, now I have some yucked up numbers on my block.

[johnta1]

What's the casting number on your block? 303 block?

[ho428]

Here's a pic of the number 48189*** can't read the rest.
I don't recall but either cast in 69 or 70, I don't have that info with me. 4 bolt, std 400 bore, large distributor hole, valley braces.

We tried identifying this on the board last year, but no one could find that casting number.

[Gasman]

I found these markings on my heads,seriously ported 670`s,is there anyone who know something about these numbers?