Reading a Build Sheet - Pontiac GTO Forum
User Tag List

 
LinkBack Thread Tools Display Modes
post #1 of 8 (permalink) Old 09-11-2018, 03:26 PM Thread Starter
 
Join Date: Sep 2018
Posts: 8
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Reading a Build Sheet

Received my build sheet from PHS. Notices that the "ENG or MOTOR UNIT NO contained the correct 78XW that matches my engine, but it also contained a -590364 after 78XW or 78XW-590364. Does anyone know if the 590364 number should match the 6 digit number stamped on the engine block? in my case below the 78XW?

Much appreciated.

John
s27519 is offline  
Sponsored Links
Advertisement
 
post #2 of 8 (permalink) Old 09-11-2018, 05:37 PM
 
PontiacJim's Avatar
 
Join Date: Dec 2012
Location: Gastonia, NC - Born & raised in Connecticut - 31 years
Posts: 3,451
Mentioned: 0 Post(s)
Tagged: 1 Thread(s)
Quoted: 347 Post(s)
Garage
Quote:
Originally Posted by s27519 View Post
Received my build sheet from PHS. Notices that the "ENG or MOTOR UNIT NO contained the correct 78XW that matches my engine, but it also contained a -590364 after 78XW or 78XW-590364. Does anyone know if the 590364 number should match the 6 digit number stamped on the engine block? in my case below the 78XW?

Much appreciated.

John
VIN numbers were not stamped on the 1964 block. The 6 digit number is the Engine Sequence Number or Engine Unit Number (EUN) used at the factory. This is sometimes found on the PHS documents.

Another way to verify if original, is to look at the cast date code on the block near the distributor hole. If it is within about 6 weeks of the build date of the car, then good chance it is original. You can also break this down further and start checking head casting dates, and assorted part numbers like intake and exhaust manifolds, carb, distributor, etc..
PontiacJim is offline  
post #3 of 8 (permalink) Old 09-12-2018, 10:20 AM Thread Starter
 
Join Date: Sep 2018
Posts: 8
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Just more questions

Thank you PontiacJim for the details. So if I understand this correctly, can I assume that if my build sheet shows a motor unit number and it does not match the one stamped on my block that it is a non matching block for my car?

Appreciate the input.
s27519 is offline  
 
post #4 of 8 (permalink) Old 09-12-2018, 07:01 PM
 
PontiacJim's Avatar
 
Join Date: Dec 2012
Location: Gastonia, NC - Born & raised in Connecticut - 31 years
Posts: 3,451
Mentioned: 0 Post(s)
Tagged: 1 Thread(s)
Quoted: 347 Post(s)
Garage
Quote:
Originally Posted by s27519 View Post
Thank you PontiacJim for the details. So if I understand this correctly, can I assume that if my build sheet shows a motor unit number and it does not match the one stamped on my block that it is a non matching block for my car?

Appreciate the input.

Yes, that is correct. If the original engine is long gone, what some will do is find a replacement engine having the correct letter code as yours does which matches the build for your car. Not a perfect replacement of course, but it can satisfy many as opposed to slapping in a different 389 block from lets say a 1966 Bonneville and then adding the 1964 heads, intake, carb, exhaust manifolds, etc.. So it is as close to "original" as you could get without having the original engine. Some will even go as far as locating an engine having the casting date codes that would correspond with your car's build date.

So value wise, not a big loss in my book because it does have the correct letter code to match what your car was born with and as long as the rest of the engine components also match the engine as it was originally assembled. If I sold the car, I would point out that it was not the original engine, but has the correct 1964 block letter code and matching engine components as would have been original to the car.
PontiacJim is offline  
post #5 of 8 (permalink) Old 09-13-2018, 05:34 AM Thread Starter
 
Join Date: Sep 2018
Posts: 8
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Thank you for your knowledge and response. I now can state what I actually have. BTW the 78XW engine has all the proper date codes part stamping that match such as the heads, intake and exhaust manifolds. Thanks again.
s27519 is offline  
post #6 of 8 (permalink) Old 09-14-2018, 09:49 PM
 
Join Date: Jun 2015
Location: Arizona
Posts: 601
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 78 Post(s)
Quote:
Originally Posted by s27519 View Post
Thank you for your knowledge and response. I now can state what I actually have. BTW the 78XW engine has all the proper date codes part stamping that match such as the heads, intake and exhaust manifolds. Thanks again.
Curious. What is the Engine Unit number on the PHS docs and what is the Engine Unit Number stamped on the block? How close are those two numbers?

Sent from my SM-G930V using Tapatalk
Shake-N-Bake is offline  
post #7 of 8 (permalink) Old 09-16-2018, 06:51 AM Thread Starter
 
Join Date: Sep 2018
Posts: 8
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Reading a build sheet

My number starts in the 552,000 range the builds sheet shows in the 590,000 range.

Any thoughts you can share is appreciated.

Thank you.
s27519 is offline  
post #8 of 8 (permalink) Old 09-16-2018, 03:45 PM
 
Join Date: Jun 2015
Location: Arizona
Posts: 601
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 78 Post(s)
Quote:
Originally Posted by s27519 View Post
My number starts in the 552,000 range the builds sheet shows in the 590,000 range.

Any thoughts you can share is appreciated.

Thank you.
No more thoughts other than what has been posted. Not original engine but a suitable replacement. Donor car preceded your car. All engines were assembled at the same place and then shipped to the various assembly plants around the country.

What I was hunting for is the possibility of a single digit variance.....in any of the decimal positions. If that were the case, then we could plot out casting dates and compare with other EUNs and determine if a typo or production error was in play. Stuff like that has happened, but of course not the normal situation.

Doesn't sound like we have anything like that happening here. Just a more common story of original engine required replacement at some point along the line. Based on the intended use of these cars..it is to be expected the engines would be one of the first things to fail and require attention.

Sent from my SM-G930V using Tapatalk
Shake-N-Bake is offline  
Sponsored Links
Advertisement
 
Reply

  Pontiac GTO Forum > The 1964-1974 Pontiac Tempest, Lemans & GTO > 1964-1974 Tempest, LeMans & GTO Data Plate, Vin Tag and Drive Train Numbers

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Pontiac GTO Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
reading a 1970 build sheet - Arlington Plant truetriplex 1964-1974 Tempest, Lemans & GTO General Discussion 2 10-20-2017 03:39 PM
build sheet 1bad69 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring 8 07-14-2008 10:35 AM
Still a new guy - Question Time - Build Sheet 70455goat 1964-1974 Tempest, Lemans & GTO General Discussion 14 06-11-2008 07:19 AM
1972 build sheet location Markwerner 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring 1 04-17-2008 09:16 PM
1971 Build Sheet 1971GOAT 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring 6 02-06-2008 08:25 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome