Unless the corner-to-corner flatness of the deck exceeds about .004", there's no reason to deck the block; quality composition head gaskets will seal that with no problem at all. If you deck the block, you might as well just set fire to a stack of $100 bills.

 

BADBIRDCAGE is right on. i build my cars to run, not to trailer to a ncrs event and have some judge look and say " hey, thats the wrong cotter pin there and its not bent right, thats a 200 point deduction" . i would be pissed if i looked at my engine and it had the right number stamped on the pad, i would have to start replacing the 1000 other non origonal parts on the car and stop driving it, buy a trailer, get obsessed with ncrs, just to have the judge say " that paint on your knuter doesnt have the right gloss, thats a 200 point deduction" id end up like this.. if you cant beat the snot out of it its not a vette

 

I like your Opinion, but, think about this: Some guys go for looks, and some guys go for Cooks!!! Al W.

 

It has gotten so ridiculous with counterfit stamps and build sheets that "matching #s" does not even indicate an original motor anymore.

If it is not documented to be original block that came with the car "matching numbers" advertisement is a good indication to look for a scam to get your money

Doug

 

but my guess are that a shops with a CNC machine are few and far between.

 

That's correct - most shops just have a conventional single-axis rotary mill, not a multi-axis CNC mill as shown below.

 

Actually I can say that you are wrong. To me, it is a used car. A used car has a value. If you and I agree on that value then we do business. If we do not agree on a value then we don't do business.

I appreciate the numbers correct people and may the Lord bless them. I am just not one of them.

Here is my take on it. I would pay you 50K for an all correct 67 435HP coupe. It is a used car, make that a valueable used car.

I would pay you 100K for a properly constructed restomod on a modern chassis like an SRIII with modern engine and drive train and braking system. Once you have constructed this vehicle and driven it it is a used car. Make that a valueable used car (to me).

I gotta go along with if the NCRS accepts restamped blocks of a "correct" period then to me they are actually endorsing fraud which is a crime. After all, we all know that only one block left the factory in that car with that number stamped into it. Now that there are two carrying the number one of them is a fraud.

The numbers matching thing has been beaten to death again and again and I am not intending to restart it. I simply tell you where I come from.

When I worked in an automotive machine shop in the late 60's, 70's and early 80's we used a Storm Vulcan manufactured machine for block resurfacing (decking). The machine used a segmented grinding wheel and aligned the deck surface with the main saddles as the mounting platform ran directly through the main saddles. We could control the movement of the block forward and reverse and could stop the grinding/cutting action of the machine prior to engaging the stamp pad. SOOOOO, you could deck a block and maintain the original numbers in the block if you wanted that. I don't have experience with other machines so I don't know what their control abilities were relating to saving the pad.

We CAN all get along. But we do NOT have to agree on everything.

Rich

 

I think the Mona Lisa looks like ****. Something I could have painted given enough time. I would not even hang it in my house, but I certianly would not throw it away. Someone, somewhere, thinks it's priceless.

 

I have had two done on a Bridgeport with good results, just finding someone that will take the time to do it for you. I have seen two on the judging field in the past year that have had the block decked and did not disturb the pad. You can see a fine line right in front of the head. Neither car took a point deduction as the pad surface looked typical and the numbers were perfect.

 

I had mine blocked without touching the numbers pad. Just be sure he can do it. Ask him how he will do it.

 

I have six of them and two CNC lathes but I wouldn't deck a block on them. To deck a block requires a special machine that can hold a large enough cutter to completely cover the deck with about 30% overhang. Using a smaller cutter will leave tool marks that will lead to leaks between cylinders and possibly out of the block. While some of my machines could hold such a cutter I could not stop in the middle of a cut to protect the numbers. If I did, I would leave the same marks that would lead to leakage.
A bridgeport is definitly not the right machine to use. A bridgeport is a Knee type mill which has the table supported in the middle by a screw that allows for the table to be raised and lowered. This machine type had it's uses in it's day but any heavy work always caused the table to sag on one side or the other depending on where the weight was. Using a bridgeport would almost guarantee that the deck would not be flat.
If a block needs to be decked, I would have it decked and I would make sure that before it is decked that a cast of the numbers was made, that was accurate and clean. I would then have the block decked and I would grain the stamp pad to mimick the broach that originaly decked the block. I would then have the cast of the numbers used to creat an exact positive of the original numbers using an EDM machine. I would then have that stamp pad pressed into the block to give you the exact pattern that you had before.
To have a numbers matching block running with a warped deck just to protect the numbers is short sighted in my oppinion, as the head gasket with uneaven preasure could let go at any time and cause the block to overheat and crack. The other problem with a warped deck, is that it could also cause your heads to crack.
If you want to save your investment and keep the numbers, I have shown you the way that it can be done while getting the motor right. The process that I described, would not be cheap, but if you want the original stamp it's the only way. Now I know that some will say that this method would not be the original stamp... but who could tell, it would be the identical stamp that was there before and who cares if it was stamped 40 years ago or redone as an exact duplicate of the original stamp a year ago.

 

Yea, but would you give away $10K in vaule of you car is the bigger question! There are lots of people who would not pay a premium for a numbers matching engine, but not very many that would willingly give away $10K in value if they already owned one! Your response, basically telling this guy to flush his money down the drain, is crazy! Of course, it is not your money!


Regards, John McGraw