I've been researching the cylinder heads that are on my numbers matching block but can't nail down what they are exactly. The casting number is 3973370 with a date code of J139. I believe they are 350 heads with an October 13,1969 date code, so I guess they are not the original heads. What I can't find any info on is the stenciled stamping on the front of the heads which is PPC 2644. Does anyone know what this means?
Thanks for your help
Steve

370 heads are over-the-counter replacements.
They have never been documented as factory installed on any small block.
There are cases of them being installed as warranty adjustment parts.

There are loads of past post in the archives discussing these heads, like this one - http://www.camaros.net/forums/showthread.php?t=27384

Thanks. I read a lot of threads on these heads, but am still wondering what the stencilling on the front of the heads mean PPC 2644!

I have 1 only on these units and it doesn't have your PPC stencilling.. Believe the head(s) were sent out to a machine shop and it is a way of the shop keeping track of what and when something was done to repair the head.. I'd also take a peek at the head on the bottom and try'n figure out why 1 intake valve is sooo lean.. Notes I have on 370 heads are as follows: Over the counter CDN / USA camel for 350ci engines with 300HP.
Another bit of info is they can be straight or angle plug units.. They have access. holes and are at 64cc.. Can be good for 69 or 70 engines...
Again I would think a machine shop stencilled their own identifier coding on the end of your heads...
T.
T.

370 heads are over-the-counter replacements.
They have never been documented as factory installed on any small block.
There are cases of them being installed as warranty adjustment parts.

There are loads of past post in the archives discussing these heads, like this one - http://www.camaros.net/forums/showthread.php?t=27384

FWIW - 370' heads WERE factory installed on Canadian produced Chevrolets. I had a 70 Impala back in the day and it came with those heads from the factory. They are all 1.94 Int valve.
I have Never seen any 370' angle plug heads, the angle plugs were either 492' or 292' casting.

I have 1 only on these units and it doesn't have your PPC stencilling.. Believe the head(s) were sent out to a machine shop and it is a way of the shop keeping track of what and when something was done to repair the head.. I'd also take a peek at the head on the bottom and try'n figure out why 1 intake valve is sooo lean.. Notes I have on 370 heads are as follows: Over the counter CDN / USA camel for 350ci engines with 300HP.
Another bit of info is they can be straight or angle plug units.. They have access. holes and are at 64cc.. Can be good for 69 or 70 engines...
Again I would think a machine shop stencilled their own identifier coding on the end of your heads...
T.
T.
It makes sense that maybe a shop stenciled the heads for identification since they are only stenciled in the front. Thanks and yea, I'm wondering what's going on with that one cylinder too. I'm just getting into it.
Thanks for the comments.