Block Restamping
Thread Starter
Racer
Joined: Jun 2005
Posts: 397
Likes: 3
From: Gretna La
Block Restamping
I don't know much about what to look for to recognize when a block has been restamped or not, or if a block has been restamped how to recognize a good job or a bad one. I'm attaching a picture of a block that has been restamped (not mine) and would appreciate opinions on what makes this a good job or bad job of restamping and how you can tell the difference between a factory stamp and a restamp.
Thank You
Troy
Thank You
Troy
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,926
From: Washington Michigan
There are lots of clues to look for, and there were many factory variations as well, so there are no pat answers, certainly too much to explain in a forum post.
That said, the one in the photo shows two primary "clues" - the curved machining marks on the surface, and the oversized "I" characters.
That said, the one in the photo shows two primary "clues" - the curved machining marks on the surface, and the oversized "I" characters.
Instructor
Joined: Jan 2004
Posts: 179
Likes: 5
From: RDU Triangle, NC
Restamping
Troy -
As JohnZ said, the curved machining marks indicate the head surface of this block was decked. The original deck surface would exhibit broach marks parallel the the crank C/L. How visible (light or heavy) they are depends on how sharp the broaches were when a particular block was run through production.
Although you state that the block in your picture was restamped, I believe it conceivable a very slight (say .005") decking could be done, thus removing the broach marks, but without completely removing the original stamped characters.
This subject is covered often and in detail on the NCRS site. There are also established guideline dimensions (character height and 'pack' length) for the different number 'packs'.
Best Regards,
Bob S.
As JohnZ said, the curved machining marks indicate the head surface of this block was decked. The original deck surface would exhibit broach marks parallel the the crank C/L. How visible (light or heavy) they are depends on how sharp the broaches were when a particular block was run through production.
Although you state that the block in your picture was restamped, I believe it conceivable a very slight (say .005") decking could be done, thus removing the broach marks, but without completely removing the original stamped characters.
This subject is covered often and in detail on the NCRS site. There are also established guideline dimensions (character height and 'pack' length) for the different number 'packs'.
Best Regards,
Bob S.
Racer
Joined: May 2004
Posts: 499
Likes: 18
From: Mason NH
Originally Posted by Bob Schaefer
Troy -
As JohnZ said, the curved machining marks indicate the head surface of this block was decked. The original deck surface would exhibit broach marks parallel the the crank C/L. How visible (light or heavy) they are depends on how sharp the broaches were when a particular block was run through production.
Although you state that the block in your picture was restamped, I believe it conceivable a very slight (say .005") decking could be done, thus removing the broach marks, but without completely removing the original stamped characters.
This subject is covered often and in detail on the NCRS site. There are also established guideline dimensions (character height and 'pack' length) for the different number 'packs'.
Best Regards,
Bob S.
As JohnZ said, the curved machining marks indicate the head surface of this block was decked. The original deck surface would exhibit broach marks parallel the the crank C/L. How visible (light or heavy) they are depends on how sharp the broaches were when a particular block was run through production.
Although you state that the block in your picture was restamped, I believe it conceivable a very slight (say .005") decking could be done, thus removing the broach marks, but without completely removing the original stamped characters.
This subject is covered often and in detail on the NCRS site. There are also established guideline dimensions (character height and 'pack' length) for the different number 'packs'.
Best Regards,
Bob S.
Burning Brakes
Joined: Dec 2004
Posts: 802
Likes: 2
From: North Royalton Ohio
No expert am I but rather than having stayed at a Holiday Inn I attended a seminar by Guru Al Grenning at the Pittsburg NCRS chapter this spring. So many variables were presented to us and the ones you would think were restamps were original. Best part, for me, is Al had my engine stamp pad documented already in his master catalog through a previous owner.
There were mixed fonts and even upside down characters. THe NCRS sells a book put together by Al and Roy Signor, both well respected authorities. "AUTHENTICATION LIBRARY" Volume One $50.00. If you plan to spend more than that for the car it might be a worthwhile purchase.
Two other issues stand out there is no patina [age] to the pad and the VIN is stamped too far out, they laid the tool against the head as they stamped and the location would be closer in. Again that alone does not make it a restamp. As John Z. stated too many minute details to list them all here.
Well, there's my .02 again. I gained a little knowledge and think I'm the expert.
There were mixed fonts and even upside down characters. THe NCRS sells a book put together by Al and Roy Signor, both well respected authorities. "AUTHENTICATION LIBRARY" Volume One $50.00. If you plan to spend more than that for the car it might be a worthwhile purchase.
Two other issues stand out there is no patina [age] to the pad and the VIN is stamped too far out, they laid the tool against the head as they stamped and the location would be closer in. Again that alone does not make it a restamp. As John Z. stated too many minute details to list them all here.
Well, there's my .02 again. I gained a little knowledge and think I'm the expert.
Instructor
Joined: Jan 2004
Posts: 179
Likes: 5
From: RDU Triangle, NC
Patina
Originally Posted by 2toys
patina [age]
I think (maybe it's just 'hope') that this would be the hardest part of the pad stamping to fake.
Here's mine.....which I think shows good patina, etc:
Best Regards,
Bob S.
Racer
Joined: May 2004
Posts: 499
Likes: 18
From: Mason NH
Originally Posted by 2toys
No expert am I but rather than having stayed at a Holiday Inn I attended a seminar by Guru Al Grenning at the Pittsburg NCRS chapter this spring. So many variables were presented to us and the ones you would think were restamps were original. Best part, for me, is Al had my engine stamp pad documented already in his master catalog through a previous owner.
There were mixed fonts and even upside down characters. THe NCRS sells a book put together by Al and Roy Signor, both well respected authorities. "AUTHENTICATION LIBRARY" Volume One $50.00. If you plan to spend more than that for the car it might be a worthwhile purchase.
Two other issues stand out there is no patina [age] to the pad and the VIN is stamped too far out, they laid the tool against the head as they stamped and the location would be closer in. Again that alone does not make it a restamp. As John Z. stated too many minute details to list them all here.
Well, there's my .02 again. I gained a little knowledge and think I'm the expert.
There were mixed fonts and even upside down characters. THe NCRS sells a book put together by Al and Roy Signor, both well respected authorities. "AUTHENTICATION LIBRARY" Volume One $50.00. If you plan to spend more than that for the car it might be a worthwhile purchase.
Two other issues stand out there is no patina [age] to the pad and the VIN is stamped too far out, they laid the tool against the head as they stamped and the location would be closer in. Again that alone does not make it a restamp. As John Z. stated too many minute details to list them all here.
Well, there's my .02 again. I gained a little knowledge and think I'm the expert.
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