Help me win this argument 400 in a 72.

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GDL

GDL

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Ok, so the wife has a 72 dart with a dying 318. I found a running 400 with 2 trannys for cheap. My father in law says pass....

So what all is needed to shoe horn this puppy in? Headers and motor mounts? Will the tranny bolt in just fine?

Basically I need you guys to make a quality post so I can show my father in law? And can you guys say what's needed or has to be done? Yes I know how to search but my father in law doesn't want to read 8 different threads....

And I'll be using his rig to haul it, his shop to install it do yea, he's part of tge equation...
 
Pass. A good-running 360 will damn near drop in, weigh less, handle better, and likely out run it.

Edit: highly likely.
 
You need to shorten your driveshaft to swap from 904 to 727. You need special conversion mounts and expensive headers. The cooling system may need to be upgraded. The 400 will be fast with a mild cam and stock thermoquad. Stock their compression is real low not a lot you can do without changing the pistons. A performer intake will lighten it up a little.
 
I found a 360 right down the road from me for the same price. So yea.....
 
The k-frame or motor mounts, radiator, exhaust, possible steering, driveshaft, and possibly rear end will have to be changed for the 400. IF you're going to that effort, i wouldn't waste it on a smoggy old 400.

The extra weight of a big-block makes for a car she may not like driving, especially if the power steering gets tossed. I want a 440 Valiant, but it would be a straight-line highway bruiser, really.
 
That was a pretty short argument .
 

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Yes it was short. And I bow to the collective wisdom.
 
I say big block, but it is some work. I've got a small block A-body (68 GTS convertible 340/auto) and both of my sons have big block four speed A-bodies (67 Barracuda fastback and 67 Dart GT convertible). None are road worthy at the moment, but I have never driven anything near as fun as my son's Dart. For many reasons (including so that my wife can drive it) my Barracuda convertible is getting a 727 behind the 440. So, you know where I stand and I've got a spare, buildable 340 sitting in the garage...
 
How early of a 72 model year block if it is. There is a pretty desirable early 400 block.
 
360 and 400 motors are 70's smog motors. from the factory they came with
0 horsepower and 0 torque, compared to their older siblings 340 and 383.
 
fishmens67 said:
360 and 400 motors are 70's smog motors. from the factory they came with
0 horsepower and 0 torque, compared to their older siblings 340 and 383.
Click to expand...


A 360 has zero torque huh....that's funny....(but 100% wrong)!!
 
I guess my day has passed. I'm from the days when mopars had real factory horsepower and for just a few bucks and a good tune, you were off and rolling. no stroking,special pistons, fancy heads, etc. you had raw power for a reasonable price.
 
PoisonDart74 said:
Yay for the 360, better yet Magnum 5.9.
Click to expand...

a 400 with 9.5:1 or so compression pistons (like kb240's) and alum heads will walk that 5.9 magnum like a dog. even without a stroker kit ( the real expensive one with a set of kb215 pistons and 440 forged crank lol)

he should get both engines and build the 400 for a later upgrade

in case you dont believe me... here's a guy with a 383 doing a 9.8 second pass in a 3100 pound car:
[ame="http://www.youtube.com/watch?v=9K6ard18yo8"]http://www.youtube.com/watch?v=9K6ard18yo8[/ame]

he goes by "Hutch" on moparts, he listed his combo in a thread over there. it's basically an 11:1 compression 383 http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Board=Racer&Number=7491454&page=4&fpart=2

the interesting thing is he has been using this engine for 5 years.
that is a LONG lifetime for a bracket engine lol
 
Buy the 400 and trannys if they are reasonable. If it's a '72 assembly and the block was cast in the first half of 1971 some misguided souls will pay a lot more for it. Regardless, sell the big block stuff and take the profit and get that 360 in there. It's easier, and you'll be just as happy.
 
400 CI = boat anchor unless stroked. 383 > 400 - 383 > 440 in an A body. 440 > 383 in anything else.

Headers are roughly $650 from Shumacher and $175+ for mounts.
 
GDL said:
Ok, so the wife has a 72 dart with a dying 318. I found a running 400 with 2 trannys for cheap. My father in law says pass....

So what all is needed to shoe horn this puppy in? Headers and motor mounts? Will the tranny bolt in just fine?

Basically I need you guys to make a quality post so I can show my father in law? And can you guys say what's needed or has to be done? Yes I know how to search but my father in law doesn't want to read 8 different threads....

And I'll be using his rig to haul it, his shop to install it do yea, he's part of tge equation...
Click to expand...

I see "wife's Dart" and her dad doesn't want to install a 400 in his shop. Do you need to be hit with a bigger stick?

Bolt in a small block.
 
400 a boat anchor unless stroked??? Bigger bore than a 440, stroke of a 383. Sounds to me like if built right the dang thing would be a screamer like a 340.

But the 400 would need more to make it work. It's your call. If both the 360 and 400 need rebuilt then it all depends on how much extra work you want to do.
 
These posts about big blocks being slow boat anchors and difficult to install crack me up. I bet you'll find very few of them making these comments have ever built or even driven a big block A-body; Bob Shingler and Jim Musk definitely not included in those I'm referring to. Do some research and you'll find it not to be the case. Take a look at http://www.bigblockdart.com and you'll see differently.

If you're a fabricator, you can easily convert your SB k-frame to BB, I believe Bob even posted procedures on how to do it, or you can buy conversion mounts if you're not. Tranny mount is the same. You'll need headers, but you don't have to buy them brand new unless you have green to waste; take a look at craigslist, eBay, swapmeets, and for sale sections on numerous MOPAR related websites. As previously mentioned, you'll have to shorten your drive shaft.

Whether you choose BB or SB, good luck with your build.
 
Stolen from a moparts thread about a 400
mopartsforum said:
This is my sons street car Dart. It has a stock stroke 400 with .030 over KB pistons and stock rods. Comes out to 406 cubes. He uses 10.6 comp with Eddy RPM heads and the MP .557 cam. RPM intake with 750 DP. With 3.91's at 3550 race weight he has run 11.40's @ 117 driving to the track. Ron

119312258.jpg
Click to expand...
 
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