400 Block...what to look for?

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Stepper

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I have a lead on a complete 400 engine for sale near me for $250.00
It came out of a 76 Cordoba with approximately 80k miles.
It has all of the pulleys, belts, ac compressor, complete from oil pan to carb.

I don't want critiques that I should avoid it or pick a different engine. I've already read all of those debates:).

What I'm interested in is if y'all have advice on any specific casting numbers or other possibly 400-specific things to look for.

More importantly are there any cardinal-rule items to avoid if they are present.

Once again...thanks. as always...this site and it's members are great.
Hopefully, if the purchase works out....this will be going into my 69 dart. :toothy10:

Thanks,
Stepper
 
if by chance the last 3 numbers of the casting number on the side of the block are 230 you have the best one. other then that go for it you can't get a better deal for a motor with everything on it for that good of a price. oh, if you don't have a 727 you might what to give it a go.
 
i think they are all about the same as for as the 400 go..ive read that some claim thicker here or there but ive read most or the same ...as long as it dont have a hole in the side or need a sleeve you you should be ok...whats the plans for it might get a little more help...anyway once you get it have it sonic and check your #'s just my 2cents mike
 
Get her disassembled then get the stripped block (all the plugs) hot tanked and crack tested before spending any more money, she should be good. Then while she's in the shop get the mains alignment checked along with the lifter bores and then bush the lifter bores, cuss you know you really want to go roller cam. Don't forget to have the deck trued. Now shop around for a forged 440 crank and the rods and pistons to stroke this puppy to 451 or just get a hold of, lets say, 440 source or Hughes and buy everything from them. I'll be go to hell. This all looks familiar, I remember now, this is what I'm doing.=P~

http://www.arengineering.com/articles/451.html

The last 3 casting numbers being 230 mean that's the block with the thicker main saddles. There's a article kicking around that talks specifics just can't find it.
 
If it's running condition, look for any broken ears or obvious damage. If it doesnt have any, have it cleaned and then sonic tested if it's for a stroker. If it passes that, have it magged and go.
 
I've read from numerous sources that that even the "weakest" 400 casting is still more stout than any factory 440 casting. Perhaps a 230 casting number could handle a few more horses but I think it won't really matter which 400 casting you're using in most situations.
 
Your right blackhand. All 400 blocks are extremely strong,the best mopar ever produced.
 
Well, thanks you guys, I scored big today!

I picked up a 76 400 complete from carb to oil pan with A/C and the HP manifolds today for $250.00

Thanks guys
 
Stepper said:
Well, thanks you guys, I scored big today!

I picked up a 76 400 complete from carb to oil pan with A/C and the HP manifolds today for $250.00

Thanks guys
Click to expand...
i pick up a 1967 383hp engine for 250.00 it even came with the #699 oil pan.
 
Used be said that the 76-78 400s and 440s were thin wall and should be sonic checked if getting bored over .030 over.
 
72BBSwinger said:
Used be said that the 76-78 400s and 440s were thin wall and should be sonic checked if getting bored over .030 over.
Click to expand...

According to "How to Build Max-Performance Mopar Big Blocks" this is largely a myth. True, Mopar Performance did publish that 76-78 block had thin walls and should not be bored more than 0.030" over but sonic testing has shown that late model blocks actually tend to be thicker than earlier blocks. The book goes on to state that quality control may have decreased during these years and that the blocks may subsequently be more prone to core shift.

Either way, I would feel more comfortable putting my hard-earned money on a pre-'76 block. You should have it sonic checked regardless though.
 
Any 400 block will be ok. The overbore thing is a huge myth.

Don't listen to anyone saying "get a different" motor. 400's have serious potential. My '65 Newport has one and it suprised me-even in that boat!
It does have 452 heads and a Hughes camshaft though.

Somewhere around the mid 70's, they started the figure 8 cooling passages and I like those for the extra cooling capacity. That said, I'd build any 400 without hesitation. I have one that I am going to tinker with when the funds allow.
 
My 400 block in mine is a 76 model and it has an old Jim Hale stroker kit with .020 Arias pistons. I have been beating on this thing since 1994 when it was in my Ramcharger. People what's in it I tell them its an old stationwagon motor. The Chevy guys think I'm lieing when I tell them it has stock rods,heads are 452s,stock rockers and shafts and even the harmonic balancer is stock. Has got me to 11.96 at 112 at 2300ft elevation!
 
The important thing to remember is that the 400 is a damn good block, no matter what year. If you're looking to build a stout stroker street engine that's capable of an easy 400 plus hp, then any year 400 should be able to take that and more if it's in good condition. If your goal is to build an all out drag racing engine with max wedge port heads that pulls close to 7,000 rpm, then you're going to need a bullet proof bottom end and it may be worthwhile to seek a pre '76 block.

The truth is that there may be no difference at all in wall thickness or casting quality amongst the 400 blocks. But if you're going to push it to the limits of what a stock block can handle, then why risk it? Pre '76 blocks cost about the same. I have a '78 400 in my barracuda and my plan is to build a 500 stroker making roughly 500 streetable hp out of it. I have no doubt that my '78 block would be great for that but I haven't ruled out switching to max wedge heads later on and for that reason I think I may end up looking for a pre '76 block to build my 500 out of.

Good luck :D
 
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