This is an original numbers matching engine that I had decked as part of a performance rebuild. I took pictures of the engine numbers before the machine work was done. There was some hope the machinist could save them, but that didn't happen. Now, I would like to have the original numbers re-stamped into the block. Maybe, this is a waste of time and money and I shouldn't bother. Does anyone have experience doing this, who can do it and what is the cost? I was told there is an acid treatment that will bring the number shadows back out of the metal. Is there any truth to this?

 

This should be entertaining...

 

Lol...

Save your money...no way you will ever be able to prove its the same block now.

 

Just because I'm curious, why was it so important to deck the block?

 

Yup here we go again Too bad the OP didn't ask BEFORE had the block decked. Expensive mistake.

 

 

OK, it wasn't well planned...but let's give the guy some advice. Clearly, if you have a build sheet or tank sticker, that's gonna help a lot to support your originality. I don't know of any way to pull the shadows of the original stamping out, but try that first.

I'd do this, first, take pictures of your block casting date, as well as the blank pad. Also take pictures of the stamping on the tranny. Keep all these together with the pix of the engine/numbers from before it was decked.

Put together a brief "letter" explaining the decking, date, etc. and you and your builder sign it. Probably better to admit to your mistake than to try to hide it now.

The next steps are controversial, and optional, unless you want to have it judged and don't want a deduct for the stamp pad.

Find someone out there with the stamping equipment (there must be a bunch out there) and get all the right numbers, codes, etc. Make sure they jibe with the font on the tranny and the "before" pictures.

Practice stamping on some old sheet metal or heads or something until you get it right. Then whack the pad.

All is not lost. I think that as long as you come clean, and have documentation (especially the build sheet) it's plausible that the next buyer, and those that follow could believe the story. It's a heck of a lot better than trying to hide it, then have a potential buyer determine that the numbers aren't quite right for one reason or another and you have to back-pedal, then telling the story, which at that point sounds fishy.

 

Just get it restamped - if its the original motor the block casting # and date will match everything else.

I am firmly convinced many high dollar cars today are fakes - I recently bought some lower seat frames from a guy with both '68 and '69 BB cars. I was looking at the '69 thats all badged up as a correct # 427. Engine pad was stamped CE and had his correct '69 VIN but the block cast code denoted a '74 454 block Non neutral harmonic balancer was a dead giveaway as well

Another example.........I was dropping off parts at my engine guys shop for my Camaro build - he had a '54 265ci Vette block on the bench getting refreshed. Guy paid 100K several yrs ago for a pristine matching #'s car. As he was lightly cleaning the surface a chip from the engine date code came off. Appears someone JB welded over a letter to change the month code on the block. It was a very good fake job but still a forgery.

We are talking 40+ yr old cars here and the value spike during the mid/late 1990's drove a lot of foolishness

The reason for decking is that most perf builds use alum heads and they are best suited using composite .039 - .041 head gaskets. Only way to get quench in the desired .040 -.045 range is then to deck the block.

Good luck, Ed

 

Support in what way? A restamp is a restamp.

 

I understand this is an old issue and I have been around long enough to be aware of it. My car is bracket raced and the matching nunbers is of no importance to me, but I am thinking of a future owner. The car was an NCRS show car before I decided to modify and race it. The block was decked to increase compression and performance. I did ask the machinist before decking if the numbers could be saved, but it didn't work. My purpose in asking about a process to raise number shadows was to prove the block is the original. I would never attempt a fraud. My 69 has a non matching 69 L79 engine that had an offer to re-stamp with GM stampings. I declined on moral and ethical issues. I only wanted to know if anyone was familiar with raising number shadows and experience with re-stamping an original block. My machinist already agreed to sign any document authenticating the engine as matching before the work was done. Thank you for the helpful advice, it seems my only option is to provide supporting documents to prove the engine is the original. In reality, even for a VG condition, fully optioned 79 the value wouldn't make much difference with all mumbers matching. It has so many other modifications, it would be advertised as a restomod not all original.

Someone mentioned a chemical process that raised numbers lost in metal and I thought someone might tell me more about it.

 

Mike--if you actually READ the rest of my post, I indicate that he could leave the pad blank and then have documentation signed by the engine builder and the owner indicating that it had been decked. The build sheet would jibe with the proper engine type and the cast date would substantiate the consistency of dating, as well as the blank pad would complete the circle.

I only wrote that the restamp was optional for judging.

 

Forget it. The pad surface has lost the original broaching marks and probably now displays typical rotary mill swirls only. That kills 38 points in judging. The VIN derivative and engine machine code have toolook like typical productions stamps in spacing, font, height etc etc. and not just have the correct numbers. Trying to explain how the pad got stamped after the pad was decked on a rotary mill and convincing the judges that it's factory typical won't happen. That's 25 points each, so a complete deduct for the pad.

Even if the acid test thing worked (and I've never heard of it being successful) a potential buyer still ends up with a blank decked pad or a bogus restamp.

A pile of paperwork and statements from the machine shop will help explain what happened but who's to say that the engine in the car is the one they decked? How does the OP know it's the original block and that the shop didn't swap it?

Sorry to be harsh but decking blocks while saving the numbers is not a 'maybe' thing. A decent machine shop can easily stop the mill short of the pad. I've seen it done and judged a top flight car at a national several years ago that got no deduct.

 

Next time just cut about and 1/8" out of the block with the number in it, then just epoxy it back in after the engine work and the original numbers and broach marks still there. I would never trust anyone with my numbers , I keep mine in my safe.

 

I didn't mean to diss anyone and appreciate everyone's input. It would appear my only option is the one I have taken. My block deck work and original numbers has been authenticated by my machinist. My feeling is that way too much value is placed on original numbers, but for limited production cars understandable. The prices bid for unoriginal restomods at Barret Jackson supports a strong interest in modified cars. It will never be judged as long as I own it, so the next owner will need to be a performance enthusiast.

 

doesn't matter.. If I am a buyer, looking for an original engine car, I would run from any seller offering me a sworn statement documenting that some machinist accidently milled off the numbers. documentation does nothing to prove any part on the car is original. only if the owner is the original owner does he know for sure. Then he has to convince his buyer. any buyer who buys a claimed original engine car is actually making a leap of faith. knowledgeable buyers may minimize that leap of faith, but it is always there.

 

Well, you should pay heed to Mike W.'s admonishment. If you are going to deck your block and do a restamp, at least make a good attempt at trying to duplicate the factory appearance. Shoot, with a little effort, you could limit that deduction to only 10 points...or maybe none at all. Of course, it will never be 'original', but...[apparently]...it would be much "better" if it looked like it was.

I have to ask... What [decent] engine builder can't shut the mill cutter down before it gets to the engine stamp? How hard can that really be? I guess if you want to keep your original pad, you have to put a penalty clause in the engine work order for the estimated amount of "lost value" to your car if they mill the numbers off.

 

I've been trying to be creative and helpful here, unlike others. I agree, go ahead and try to recreate the parallel broaching (I've read that some coarse sandpaper works with a belt sander) and get the right fonts and restamp. It is the original engine for God's sake.

Alternatively, not in this case, but if you have to rebuild the engine anyway, take out the original block, cover it in plastic and store it. Replace it with whatever works, rebuild and keep the original block with the car.

 

I don't mean to toss fuel on a fire but.......I don't understand why restamping a block is any more of a misrepresentation than a brand new date coded windshield , radiator , plug wires or anything else that is dated or stamped. I have read it here many many times " its only original once". so in my opinion , original means tires, belts ,hoses, brakes you name it. so if you say your car is " original " and you have changed anything , is it fraud or misrepresentation?

 

I have to say, I am sorry I asked this question here. I didn't ask for a lecture about decking off engine numbers and the merrits of keeping a car original. If I really cared about all the nonsense of decking the block and originality, I wouldn't have decked the original block and used my spare 010 block. Having a car set in my garage forever and afraid to use it doesn't make sense to me. My car is so far from original, it will probably never be put back to stock, even though I have all the original parts. Yeah...I know the tune about never being original again and blahblahablah. To each his own. For all those who praise all the original Corvettes, no matter what year and collectability: I hope you enjoy going into your garage, sitting behind the wheel and making motor noises while moving the steering wheel and simulating driving. This doesn't get it for me. I didn't ask about raising number shadows to get a lecture about the horrors of decking numbers off the block. I prefer to use the car and enjoy it and part of that is modifying it. If making a car perform and look better than factory makes it worth less, so be it. To each his own, but I'm not going into my garage to turn on my car radio and make motor noises because I want to keep a car original. For those who offered their best advice to answer my question, thanks! For all the rest

 

If you don't care about the numbers, why ask the question?

You've been a member here for 6 years. I'm sure you knew what was going to happen.