400's are they any good?

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66plyValiant

66plyValiant

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I have the chance to get a 400 BB and a matching 727 transmission from a 70' s chrysler newport for free from a guys parts car, only thing I have to do is get his car he is fixing up running for him and he will give it to me. Are these 400's any good or are they boat anchors? are they a B block or RB? I'm looking to put it into a 77 dodge 1/2 ton. sorry for all the questions I'm more familuar with the 440's and 383's
 
400 is the strongest block ever made by chryco. Get it!
 
The problem with B block 400 engines are;

Low compresion, dead low.
Broom stick cam

Valve sizes are small, but! They are good for the size of the engine unstroked as the allways quick mention is to do with these things is. And not a bad idea ethier. A 451 or 500 ci stroker kit is a on the shelf item.

They come with the everything the 383 is famous for (Except above) plus a few more inchs. If a on the cheap hop up is the goal, you'll need to mill the heads down some for a decent ratio and install a cam/timing chain in it to get ya going.

If a TQ aint the carb for you (850 cfm size perfur'd) then look at a 750 cfm squarebore size to start. Equip as normal, like any other engine.
 
400's are very good foundations to make potent powerplant. Very strong and are easily stroked.
 
Stay away from the lean burn stuff though.

put in points or just a standard 383 electronic ignition.
 
I'm not convinced that you always have to build a stroker to be happy with a 400. It is a good route to impressive power with a 451 build though.

I have a 400 in my '65 Newport that runs very good considering how heavy the car is!
*Hughes cam with matched valve springs
*452 heads
*Double roller timing set
*Edelbrock Performer and modified 600 Holley.
(Intake was an improvement over stock but NOT an overwhelming one compared to the iron 383 4 barrel unit that was on there)
The '65 Newport is my daily driver and this is a smooth yet fairly economical setup. Way cheaper than making a car payment!!


If it was an A body, it would be tons of fun. I'll take any 400 that nobody wants!!

It is the highest strength block hands down-capable of handling serious power!!
 
Definately get it. Most folks like them for potential and availability of parts for stroking a 400 but they are stout with a few mods also. We have a guy in our local club that put a 400 built to similar specs. as DusterKrazy in a 70 Dart and it was running high 12's first time out.

Oldschoolcuda
 
DusterKrazy said:
I'm not convinced that you always have to build a stroker to be happy with a 400. It is a good route to impressive power with a 451 build though.

If it was an A body, it would be tons of fun. I'll take any 400 that nobody wants!!
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My exact route. If a stroker dosen't come to me so easy in the future, I really do not think a rebuild of it is out of the question. The 400 has expensive (By compare) pistons over some of the other big blocks, but at least they make'em new and in cast, Hyper-U and forged, dished, domed and flat top. Unlike a RB 383, 350/361 B engines.

Oldschoolcuda said:
Definately get it. Most folks like them for potential and availability of parts for stroking a 400 but they are stout with a few mods also. We have a guy in our local club that put a 400 built to similar specs. as DusterKrazy in a 70 Dart and it was running high 12's first time out.

Oldschoolcuda
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With the light body and lightening it up further, I don't see much of a problem with having a high to mid 11 second car a hard thing to do. It can even still be a easy streeable build.

There was a thread going on about A body/Duster weight. Some fellas with big blocks in there Duster were reporting 3200 and down. The engine was treated to all the aluminum parts it could get bolted on to it.

Further weight reductions would come from fiberglass body panels and bumpers. Heck, deleating the steel behind the chrome bumpers has gota be a 100 lbs on the early Dusters never mind the big ones of the later years.

If your good, a sub 3000 lbs. big block Duster is doable. :rock:
 
sounds like its a good engine, this would be going into a dodge pickup, but I knew there where people who knew big block engines on this site so I thought I would ask. thanks for the input everyone!
 
rumblefish360 said:
My exact route. If a stroker dosen't come to me so easy in the future, I really do not think a rebuild of it is out of the question. The 400 has expensive (By compare) pistons over some of the other big blocks, but at least they make'em new and in cast, Hyper-U and forged, dished, domed and flat top. Unlike a RB 383, 350/361 B engines.



With the light body and lightening it up further, I don't see much of a problem with having a high to mid 11 second car a hard thing to do. It can even still be a easy streeable build.

There was a thread going on about A body/Duster weight. Some fellas with big blocks in there Duster were reporting 3200 and down. The engine was treated to all the aluminum parts it could get bolted on to it.

Further weight reductions would come from fiberglass body panels and bumpers. Heck, deleating the steel behind the chrome bumpers has gota be a 100 lbs on the early Dusters never mind the big ones of the later years.

If your good, a sub 3000 lbs. big block Duster is doable. :rock:
Click to expand...

I wonder what my Dart will weigh in at? Fibreglass nose and all the alum motor upgrades,I think it'll be close to 3000.

I really love the 451. It's like a 440 but in a smaller lighter and stronger block,plus a recip assy thats about 10lb's lighter.. Makes for a very snappy torque monster that likes to rev..:finga:
 
Over at BBD.com they have a list in the tech section of what the weights of steel vs. fiberglass parts are with a total savings of weight to the right of the list. They show a good possible weight reduction for the A bodies.

Know your cars actual weight before making any calc's and do not go by the reggie's listed weight. Drive it onto a scale if possible (At a junk yard?) and ask for the weight of the car. Also, realize the amount of gas in the car in as close to exact gallons in the tank. I forget what the weight of a gallon of gas is. 7#'s per gallon? I do not remember. But minus that from the cars weight.
 
I love the 400 that I have in my '72 roadrunner. It's built to mostly stock specs, except for hyper-eutectic pistons, a performer intake, and a slightly bigger cam. It pulls hard all day. If I put headers and a better carb on her, she'd be a screamer.
I say definitely go for it.
 
im pretty happy with the 400 i just put in my duster but its just a cruiser.
 
66plyValiant said:
sounds like its a good engine, this would be going into a dodge pickup, but I knew there where people who knew big block engines on this site so I thought I would ask. thanks for the input everyone!
Click to expand...

Just making sure that you know that in order to put the 400 out of a car into your truck, you do need a different oil pan, pickup, exhaust manifolds, and motor mounts.
They shouldn't be too hard to find, there was a lot of Dodge pickups that came from the factory with big blocks.
 
yeah 440 mounts, pickup and pan should work if I remember correctly, I have done lots of truck to car swaps in small block mopars but this will be the first car to truck BB swap. I'm going find out more details tonight about the engine, if its seized I don't want it
 
and i remember when you couldnt give them away lol now ive been bugging this guy with a 73 Newport rotting in his yard to sell it to me for 2 yrs now..go fig, times they are a changing....even stuck for free,,grab it..your gonna bore it anyway just saying
 
ace26 said:
Check out this site, I think they have most or all of the stuff that you might need for a BB swap into a truck.
http://www.engine-swaps.com/Pages/Products.html
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I looked at there site a few times, first time when I was getting ready to put a v8 into a dakota (almost $400 for mounts!) I will probably go to napa for a new oil pan/sump and maybe the mounts or maybe the dodge dealer may have something (they did for the valiant)
 
Go to moparts.com and ask 383man about his son's 400 Dart. Pump gas, .557 MP cam, Eddy heads, very mild, very streetable...11.40 as driven on the street with 3.91's. (Well, with slicks...)

I had a 400 back in the day, (early 80's) and a Duster and no money. I decked the block to get the compression up, used a MP templete ported set of 915 heads, a MP .509 cam and TM6 intake. With a 10" converter, 3.91's, a 'glass 6-bbl hood, it finally went 12.30's uncorked on a McCreary dirt track tire. 12.60's corked up...

They need reasonable compression and they will respond accordingly.
 
I just got my hands on a 72 400. I'm new to Mopar so I'm not an expert. I want to know; If the block checks out good with magnaflux and a sonic check, and I spend the money on doing the aftermarket cross bolted mains and good high quality reciprocating assembly, say a four inch stroke for a 480 cube motor, what are the limits of this block? How much power and RPM can these motors handle? Where/what are the weak links? Can they take say 1000 HP 8000 RPM? How strong are these blocks?
 
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