I'm in the process of restoring a 1970 Dodge Challenger RT/SE back to its original Black with burnt orange interior. I recently pulled the engine only to find the area where the numbers are usually stamped are free from any markings. I was told factory replacement blocks were not stamped, any input greatly appreciated. Is there any way of getting the engine authenticated through vehicle history. Thanks

*Always looking for parts to buy/sell/trade.

Always heard that an engine replaced under warranty was not stamped.

But, if replaced under warranty... It's not numbers matching.

And if someone bought a replacement engine from the parts counter... Same story.

Do you have the build sheet or broadcast sheet? If not do you know how to tell what the "scheduled Production date " is on your car? If so look at te SPD and then the casting date on the block from your car, if the block was cast after the SPD then you DO NOT have the original block, sorry If the block was cast before the SPD, lets hope so then it is possible for it to become the "original" block More than one Mopar car that had the original "original" block destroyed or remove before the last or current restoration has ended up with a "factory replacement" numbers matching block in the car according to many internet rumors and allegations

Boy,I didn't know that !!!!!!

Check the casting date on the block.. Possibly a pre 68 block..

Did you check both the top pad by the distributor and the bottom pad by the pan rail? Top pad stamping often disappears when a block is decked.

^^^^ this , the OP doesn't say what pad is blank , we can only SPECULATE what pad has no numbers on it.

thanks for everyones input on this topic, I found the following markings on the top pad by the distributor.

S383

15

I looked up and according to the date chart, it states its from 1962, and I have no idea what the 15 stands for, Januarary 5, 1962? Are there any other markings internally, as the manifold numbers match out to a 1970 383. looks to me like someone rebuilt the engine with a 1962 shortblock? Thanks

What are the casting numbers on the side of the block? There should be a part number and a casting date. You can also look at the back of the block near the bellhousing area for a casting number.

No, that is a service replacement 383 short block, look for the casting date on the side of the block

There's a low-scruples Mopar guy in southern Oklahoma that traded me an 18 spline 833 for my bare 383 service block. The block had no numbers on the VIN pad but carried a production date that lined up nicely with the build date on his 383 RT Challenger.

Update for all that helped with info and anybody else interested. After searching and a bunch of degreasing and such I found these numbers stamped on the block.

2468130•3
3•17•71

So I gather it's a service replacement block with a born on date of March 17, 1971 and it appears just the short block was replaced and the manifold, carb, ac and such was placed back in. Does this block dated 1971 not constitute a "original" replacement block? And lastly I'm I better off finding a 440 and swapping it for the 383? I was hoping to go as close to original on things as I can. It's a TX9 car with burnt orange interior with 727 column shift. Thanks in advance as I found these forums very resourceful.

It is not the original block. It does not constitute as original. But a blank vin pad block would be the next best thing.

A 440 block is obviously wrong for the car as you can spot the pad just right of the distributor.

With the advent of inexpensive stroker kits, just put in a stroker rotating assembly. You would just be making a low deck stroker with a little smaller bore than a 400 block.

I agree. People make way to much out of the whole matching numbers thing. Mopars are stamped in the vin and fender tag to prove motor, hp, and trim. It's the Chevy crowd that started the matching numbers crap. They have to match numbers to prove the same. If you are worried about the casting date, just find a earlier cast F383 HP. HOWEVER, most premium rebuilds require milling the deck of the block in order to square the deck and get a good flat surface for the head gaskets to seal. If you mill the deck on a 383, those stamped numbers on that pad are removed. Those numbers were originally stamped for a mechanic to easily determine the internals and what cid he was dealing with.

It all depends on what you want to do with the car and how much money you're willing to spend. For an original looking driver I'd probably put a 440 crank in that 383 block with 9:1 compression and have a nice pump gas 426 engine. Just tell people the original block is gone and it has a '71 engine in it.

If you're trying to do a number matching resto then you either need to advertise for the original block (super long shot) or just accept the fact that the original block is gone and you have a service replacement.

unless you KNOW differently,
the best possible truth to your situation is that you have the engine that was replaced in your car when it was about a year old & it's been there 44+ years

keep it - that's history!

Just build what the service department put in there after a previous owner had too much fun...

The number and date you gave were not "stamped into" the block, those are the casting number and the date the block was cast and those are cast onto the block, they were there when the block came out of the mold.

Re: stroker
By the time you buy a 440 crank and find someone to reduce the main journal size and redo the rod journals you are quite a ways towards a new stroker crank and if so, a 4.25" stroke would give you 484 cubic inches. There should be off-the-shelf pistons for this stroker.

R.