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I'm looking for some info here on purchasing what I think is a 400 Ford block. Block code is D7TEA3B looking this up it's a 1977 truck block, but the last three A3B are confusing me, as all I can find is an old manual that says A2B is a 400. We measured the stroke, but can't turn the engine over so can't be certain that it's at the bottom of the stroke. I'm not an engine builder nor do I have any experience, but my 1977 f250 currently has a tired 351m that I plan on swapping out to this? 400. The bonus is it already has an edelbrock performer 400 exhaust manifold, aftermarket headers, and it's not a lot of money. Any info that would help the decision for me would be great.
I will be checking for any markings on the top of the pistons that would signify it has been gone through. (.030, .040 etc) as I am told once they have been bored out, and with the condition of the cylinder walls being rusty, it can't be reworked, its basically a boat anchor, soooooooo
Question one: With the block code provided, and pictures below, can anyone solve that mystery?
Question two: are these pistons stock as they look like they are not flat top, but a different design. Maybe Ford switched these?
Any info would be appreciated thanks!
not exactly sure if this is the bottom of cylinder D7TEA3B shows D= 1970 7= 1977 E= engine I can't find anything on A3B? cleveland forge exhaust manifold stock I was told that id the block has been reworked, it would have been stamped .030 etc of top of piston?? I don't see any markings whatsoever. Appears the exhaust vales were left open at one time as the cylinders are rusty/ carbon no visible cracks, and frost plugs all intact.
Is there something wrong with your current motor besides being tired?
The only difference between the 351m and the 400 is a crank and pistons. Block and rods are the same. This “new” motor will need a compete rebuild and the crank will most likely need to be turned down.
This “new” motor may still be a good deal for just the intake manifold.
Your current block is just fine to turn into a 400. It just needs a new crank.
Yes those are the stock pistons.
Any block that is rusted to the point it’s froze up would have me worried.
You might want to compare the cost of a new crank plus a used edelbrock intake with the coat of this 400 and the cost to have the crank turned.
The block numbers will not tell you if it’s a 400 or a 351 as they are the same block. The best way to tell is to look at the crank.
Below the left crank is a 351m and the right is a 400 (middle is a 351c) the 400 crank has a ridge in the first journal (I circled it).
Is there something wrong with your current motor besides being tired?
The only difference between the 351m and the 400 is a crank and pistons. Block and rods are the same. This “new” motor will need a compete rebuild and the crank will most likely need to be turned down.
This “new” motor may still be a good deal for just the intake manifold.
Your current block is just fine to turn into a 400. It just needs a new crank.
Yes those are the stock pistons.
Any block that is rusted to the point it’s froze up would have me worried.
You might want to compare the cost of a new crank plus a used edelbrock intake with the coat of this 400 and the cost to have the crank turned.
The block numbers will not tell you if it’s a 400 or a 351 as they are the same block. The best way to tell is to look at the crank.
Below the left crank is a 351m and the right is a 400 (middle is a 351c) the 400 crank has a ridge in the first journal (I circled it).
Thanks for that info. The whole idea is to not have any downtime, and the 400 bolts straight up to the existing plate. Either way it's most likely going to be a rebuild, but this way its pull the one out, and bolt the other in. Like I said, I'm going by what my builder/mechanic is saying, as he's the one with all the experience.
If you can't turn a worn engine by turning the flex plate by hand it's locked up.
no likely to be a rebuild to it. the condition of # 6 in itself means there will be a rebuild. or at least a repair. the valves almost have to be damaged too.
Is there something wrong with your current motor besides being tired?
The only difference between the 351m and the 400 is a crank and pistons. Block and rods are the same. This “new” motor will need a compete rebuild and the crank will most likely need to be turned down.
This “new” motor may still be a good deal for just the intake manifold.
Your current block is just fine to turn into a 400. It just needs a new crank.
Yes those are the stock pistons.
Any block that is rusted to the point it’s froze up would have me worried.
You might want to compare the cost of a new crank plus a used edelbrock intake with the coat of this 400 and the cost to have the crank turned.
The block numbers will not tell you if it’s a 400 or a 351 as they are the same block. The best way to tell is to look at the crank.
Below the left crank is a 351m and the right is a 400 (middle is a 351c) the 400 crank has a ridge in the first journal (I circled it).
Originally Posted by 440 sixpack
If you can't turn a worn engine by turning the flex plate by hand it's locked up.
no likely to be a rebuild to it. the condition of # 6 in itself means there will be a rebuild. or at least a repair. the valves almost have to be damaged too.
The heads are getting junked in favor of edelbrocks, so not too worried about them. I agree the pistons look fuzed in there.
This is indeed a 400 block. We have proved this out by:
1. Checking cylinder depth after removing the head. If it was a 351 would only measure 3.5" deep. The 400 measures 4"
2. Measured the rods (roughly) and they were around 6 1/2"long. The 351 has 5 3/4" length rods.
3. Pulled the pan and there is a faint stamp that says 5MA identifying it as a 400. Thanks to previous post there is that extra ridge where it should be.
4. Pistons appear to be stock, no visible markings as to it have been rebuilt (great news)
Sorry for the point form, but I want to be able to assist people and ID these motors, as I had quite a bit of a learning curve myself. It would have been a hell of a lot easier if Ford just stamped the blocks properly!!!
This is indeed a 400 block. We have proved this out by:
1. Checking cylinder depth after removing the head. If it was a 351 would only measure 3.5" deep. The 400 measures 4"
2. Measured the rods (roughly) and they were around 6 1/2"long. The 351 has 5 3/4" length rods.
3. Pulled the pan and there is a faint stamp that says 5MA identifying it as a 400. Thanks to previous post there is that extra ridge where it should be.
4. Pistons appear to be stock, no visible markings as to it have been rebuilt (great news)
Sorry for the point form, but I want to be able to assist people and ID these motors, as I had quite a bit of a learning curve myself. It would have been a hell of a lot easier if Ford just stamped the blocks properly!!!
Now for the tear down..............
Why would Ford stamp the blocks? They are the same block. One is built as a 400, the other as a 351M. Just like a 360 and a 390 in pickups, or a 390 and 410 in cars. Lucky you getting a 400 btw.
01-09-2021, 04:46 PM
