FASTBACK

I've got a person trying to sell me a 1968 396 engine he says is now a 427. Is that possible to do? If so, it should still be worth a lot less than a 68 427 shouldn't it? As you can see, I'm not too mechanically knowledgeable so any help would be appreciated.

earthquake68

Yes, it's possible. You need to find out what kind of 396 it was. There were MANY different castings. I took my '69 396 all the way out to 496. My engine started with .400 thick cylinder walls. Even after a .100+ over bore, it still has .250 thick cylinder walls. Plenty. That and a .250 stroke and there ya' go. 496". Can I do anything else if this engine goes away? Nope, if anything happens, it's junk. Then it's time for a Merlin block. What's it worth? An engine like this doesn't conform to the proper date code stuff. It's not a '68 427 if that's what you're after for your concours restoration. It IS a 427 if that's what you want in your car. Make sense? An engine with that much work in it won't be cheap even if it is "just a hotrod engine"

FRSTR90

No, it is NOT possible. A 396 has a bore of 4.094. On 4 bolt blocks, it has been said that you can safely do a .125 overbore, but no more than that. On 2 bolt blocks, you're limited to .060. Now, if you bore a 396 .125 over you are left with 4.219 that makes a 421. If you are not needing a 68 engine, find your self a 454 block and add a 396/427 crank.

Z-man

Well - there you have it!! Should be easy to make a decision now...

L88Plus

It depends on which casting it is. An old school hotrodder trick is to knock the center freeze plug out and check the distance between the cylinder barrels. If you can barely stick a pencil between the cylinders, it can be taken to any bore size that a 427/454 block will handle. If it's more like 1/2" between the cylinder barrels, .125 is the max overbore. As with any big overbore, have it sonic checked first.

FASTBACK

OK, not sure what to make of this yet.
I have an engine that I purchased from a guy that told me it was a 427. After checking it's casting number, 3916323, it identifies it as being a 1968 396 engine, 1 year only cast?
After approaching the guy with the information he told me it was built to 427 specs and that it is now a 427, he probably thinks he's got a real dummy on his hands, I hope he is wrong. I don't know anything about how to do that so I'm asking the quesitons as to if it can be done and of what value would it be in comparison to a 'real' 1968 427. I paid a 'real' 427 price for the engine and I think I have been taken. He thinks not. Hope this helps, thanks.

Derrick Reynolds

There is some questionable stuff above IMO, I would advise taking it with a few grains of salt. If he says "built to 427 specs", ask him what the bore and stroke are. Once you have those, the displacement of the engine is as simple as (bore*0.5)^2*3.1416*stroke*# of cylinders. If that looks complicated, all it is is "Pi R squared" to give the area of the circle of the cylinder, times the stroke, times the number of cylinders (probably 8). That will tell you if it has a displacement of 427 cubic inches. Post what he tells you. I don't remember the bore and stroke of 427s off the top of my head, but that has to be easily available on line, so you could check if that matches "427 specs", which would add credibility to the guy's story. You can check the stroke by dropping the oil pan and finding out what crank is in there. I am not sure about the easiest way to check the bore, pulling a head would get it done but I wonder if there is a way to check the bore from underneath when the oil pan is off, thereby saving a lot of work. I have never done that, but it seems like there should be a way.

wfo76

Both engines had a 3.76" stroke, but to bore a 396 to 427 would mean going from 4.096" to 4.250".
That is one hell of an overbore and GM felt a new block was necessary. Only way to know for sure
is pull the heads and measure the bore.

7T1vette

If the block casting number is not the same as a 427 casting, it isn't a 427, is it? Now, you can get 427 cu. in. out of a 396 by installing a 454 crank and adding just a little to the bore size. But, the bore and stroke dimensions aren't the same as a 'standard' 427. It all depends on what you want to accomplish. In any case, you shouldn't have paid 'stock' 427 block price for a 396 block.

Sully1882

7T1vette is right on.... if you paid premium price for a 1968 427 CI engine and it is really a 396 you got taken and mislead. I would be willing to bet there is a huge difference in not only the ability and performance of those engines but also in their prices. either way,it's not what you thought you were buying...

Sully

bashcraft

There's an easier way.

Bore dia X Bore dia X Stroke X .7854 X # of Cylinders = CID.

capevettes

Bottom line: the seller misrepresented the motor as a 427 when in fact it is a 396 that was "built" to something resembling a 427. The 427 motor is a more valuable motor. If you paid the premium for a 427 I would be looking for my money back. If you don't care about numbers and you got it cheap, it's up to you how you want to proceed. Good luck.

FASTBACK

Thanks to everyone. I really appreciate all of the information and you just confirmed what I felt.

Now the real KICKER:

The person that took me on this, that purposely scammed me, the one that takes advantage of those that trust people to do the right thing was my own brother!

The sad thing is it is not the first time. How pathetic is that? I've got to be the dumbest person in the world.

But thanks to you, he's not going to get away with this one. He'll never pay me back............ but he lost a good friend and partner.

7T1vette

You need to tell him to his face that this is the last time he'll ever get anything 'extra' out of you. Being taken by your brother is about the worst!! If it were me, total strangers would be one step up on the 'trust ladder' above him {at least, you don't know that they will try to $cr@w you...}

tnovot

But wait a minute. In the original post, he said that he was told that it was a 396 that was turned in to a 427. I believe that he was not scammed and that his brother gave a true representation of what he was selling.
Also, according to the original post, the seller is trying to sell him the engine but the purchase has not yet been finalized. If he has already made the deal, IMHO, the buyer needs to be knowledgeable about the item(s) he is buying and ask question first, not after the purchase. Just my 2 cents.
Terry.

capevettes

You are right I stand corrected and didn't read the initial post as carefully as I should have.

Bangkok Dean

I wonder if its an Chevrolet motor

bashcraft

Well, if it were a Ford, it would be worth a whole lot more. I know of several people looking for one of these.

FASTBACK

Just to clarify what happened. Reading the original post does suggest that I knew it was a 396, well that's not the case. I don't know a lot about engines and coding but I've always wanted a 427, never had one and never had a car worthy of one. I think of that engine as the best of the best. My brother has been into Chevrolets his entire life and has had dozens of 427's, 409's etc. He makes deals and trades in Chevrolets every day as a serious hobby, it consumes him, he even now and always has worked at the parts counter for Chevrolet dealers. I look to him for advice, always had to. He knew I wanted a 427 and showed me his '427' he had in his garage and sold it to me as a '427'. It wasn't until afterwards that I found out how to check block casting codes and found it to be a 396. He duped me again as he had done many years ago. Because of his duping me many years ago, we broke off contact for 12 years. I didn't even know what state he lived in. Then about a year ago I happened to see him at a swap meet and I decided to mend fences and placed my trust in him once again. This is the result of my stupidity. OK, so much for that, I hope it clarifies that part. If you want to even know more about the personal side of this transaction then read on. As it turns out, just by coincidence, I happened upon a person that knew my brother and he had a 68 Camaro he wants to sell and said my brother is helping him with it. He gave my brother a blower 327 engine that he had $10,000 into to try to sell and get him a 427 for his Camaro. He said my brother had done that for him but hasn't given him the engine yet. He printed a picture of the '427' my brother purchased for him - - yes, you've probably guessed, it is the engine that I have, the very same one and the picture was taken from inside my shop where I have it. So, if you've read this far and ever want to know how it is going to end, let me know, I'll tell you. But one thing I've got to say about this, that does not run in the family, I am still a trusting guy and would never even think of doing anything close to resembling those things that for some reason he has a habit of doing. Just can't believe, still don't believe anyone could be capable of doing something like that. I'm out completely, I'm letting the guy with the Camaro have the engine so that we're both not dragging bottom. Luckily for him, it's a '68 396 engine and will be a fitting engine for his '68 Camaro. Enough said about this whole issue, believe me there's even more about this, even more bad dealings and more people taken on other deals that I've been subjected to so let's drop it now and call it quits. OK, one more thing, as of this writing my brother does not know that I know everything and doesn't know that I now know about the Camaro guy either. I wonder how it's all going to end as it must sometime.

TopGunn

I'm getting dizzy