# Engine decoding



## Inprogress65 (May 18, 2012)

I'm wondering if someone could help me out? On the front of my block along with the WS for 400 4 speed is a 5 or 6 digit number. Does this number coincide with the vin or something? Is this maybe something I can find on the PHS doc?

Thanks in advance!


----------



## BearGFR (Aug 25, 2008)

No, it won't match the vin --- that number is an "engine build sequence" number that was used in the plant. I don't recall for sure if the PHS doc will have it, check with them.

If you look down lower on the same side of the motor, next to the edge of the timing cover, you should find another string of digits - running up and down. This number will match to your VIN if it's the original engine. I think the factories started stamping the partial VIN on blocks starting in late 1967.

Bear


----------



## Inprogress65 (May 18, 2012)

I'll have to get out there and check, thanks!


----------



## 05GTO (Oct 6, 2004)

The 5-6 digit engine unit number was listed on the PHS billing history starting in early 67, as bear said in mid 67 part of the car's vin was added to the front of the block.


----------



## Inprogress65 (May 18, 2012)

I looked around for the second number lower on the block with a mirror and didn't see anything. It may have been masked with paint I suppose. Could it have been immediately behind the water pump inlet? That may have been why I wasn't able to find it.


----------



## 68greengoat (Sep 15, 2005)

Since the engine vin is stamped, it very well could be filled with paint. Or, since the build date is the 2nd week in July(I read in another thread of yours), it may not be stamped at all. I've read where they were stamped starting in late '67. Not sure what month whether it was mid or late '67. If I remember right, the water pump inlet is in the way.... You can also check the date code cast next to the distributor. Ex D217(7 being '67).

Here's the local:


----------

