# Correct Engine Code/Date?



## leeklm (Mar 11, 2012)

Hey Guys,

While looking for a somewhat correctly dated 389 for my car, what would be considered an acceptable date range stamped on the motor? The invoice date shown on my PHS build sheet is 3/30/66.

By the way, I have a "WTB" listed in the parts section if anyone has a lead on a WS block 

I am still undecided on the motor build... I really like the thought of a 461/stroker, but if I am going to spend the $$$, would be nice to have something more correct for the car to help with future resale value.

Thanks!


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## rickm (Feb 8, 2012)

i could be wrong ,but i thought that "matching numbers" meant just that your correct engine code block has an earlier production date then build date on your trim tag. thats wy you see so many cars for sale that are supposed to be. finding a gto with the original factory block is like hittin lotto. rickm.


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## jmt455 (Mar 26, 2012)

The engine and major component casting dates should pre-date the vehicle build date by anywhere from a few days to several months, depending on the assembly plant location.

If your car was built at Pontiac, the component casting dates could be very close to the vehicle build date, but a Fremont-built car should have more time (typically several weeks) between the component casting dates and the vehicle assembly date.

Also, be sure to consider the build date on your body tag, not just the invoice date on the PHS docs. Sometimes, the car could be built and spend several days or even a couple of weeks on hold or in repair area until it was released for billing/shipment.


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## BearGFR (Aug 25, 2008)

The meaning of "matching numbers" varies depending on what year the car was built. Strictly speaking, it means that the car has the same engine block, heads, and other components that it was originally built with - not just pieces with 'believable' date codes but the actual parts. Problem is, until Pontiac started adding the partial VIN stamp to the engine blocks there was no way to verify this unless the PHS doc happened to include the engine build sequence number (above the 2 character "block code") and you could verify that.

My engine is truly "matching numbers" because even though it's now a 461, I built it using the original 400 block the car rolled off the line with. The VIN stamp on the block matches the VIN stamp on the car. Same for my TH400 transmission - it's the one that the car was built with even though internally it has been beefed up. I'm not running the original heads or intake, but I still have them - likewise the original 10-bolt rear axle that's still sitting out in my garage. 

Bear


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## rickm (Feb 8, 2012)

i understand your definition of "matching numbers" . your car is one of the few. i see so many gtos for sale that claim to be. abviosly, there not following your definition. like i posted earlier, its like hitting lotto. these cars were drivin hard n fast. the chances of a gto retaining its original drivetrain components are slim to none. rickm.


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## leeklm (Mar 11, 2012)

I do agree with the true definition of a "numbers matching" car having the original motor that shipped from the factory, but like you said, they are rare. I figured the next best claim was a "year & code correct" engine.

In reality, that would probably increase my cars value by $500. Meanwhile, spending an extra $2K (over a 400 build) to get it that way. :confused

I want to get something done over the long winter, so will not have a lot of time to hit the lottery. Something tells me I will be starting a post next spring about how much I like my new 400/461 !! and then a post after that about upgrading my drive train...


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## rickm (Feb 8, 2012)

whatever YOU want in your car is most important. i personally am happy with "period correct". good luck with your powerplant. rickm.


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