383 vs 400

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dart67

dart67

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I'm looking at 2 dusters one has a 400 and the other has a 383 mainly going to be a street machine is one engine better than the other (don't know much about big blocks and nothing about a 400)
Thanks
 
bigger isn't always better, 383

Stock the 383 had 300 or more horsepower compared to the 400 which had less than 200 (2bbl) and 225 horsepower (4bbl).

You'll find more parts and better parts available for the 383.
 
take the 400 and stroke it.

the 400 has the largest bore of any BB mopar....
 
dart67 said:
I'm looking at 2 dusters one has a 400 and the other has a 383 mainly going to be a street machine is one engine better than the other (don't know much about big blocks and nothing about a 400)
Thanks
Click to expand...

The 383 is a great engine, very powerful for its size, The 400 has the biggest bore, larger then a 440, The 400 has a low compression, but it has very good torque, what makes the 400 so popular is you can stroke it to the famous 451, those are torque monsters, I would say, just pick which one you like better, The price vs. the overall condition.
 
In stock form the 383 is by far the better engine but there are problems finding pistons for it other than KB's. With a zero decked 400 (you'll need new pistons) they are comparable. The BB heads will fit either so that don't come into play.
The winning combination is a stroked 400 (440 crank) for 452 cubes as said above.
 
I've had both motors. The 400 is a dog. It was basically a de-tuned motor to keep the government happy.
I had a 1964 Plymouth Sports Fury with a 383 4bbl automatic that ran high 14:00 in the quarter that was completely stock.
Versus a 1972 Dodge Charger with a 400 Magnum automatic that ran 17:00 in the quarter bone stock.
The 400 Magnum has a real crappy intake manifold. It has an internally built in E.G.R. valve that hurts performance. On top of that is the Thermo-Bog carburetor! Never really was too impressed with that carb.
If you can find a rebuildable 60's 383 with small chamber heads I think it would be the way to go. The 400 may have a larger bore but I'd bet on my old 383 every time.
 
given the last 383/400 were build back in the mid 70s....how many do you think are running around STOCK.......

if both engines have been rebuild...the 400 is probably not the dog that is was back in the 70s....probably no longer has the lean burn ignition and the PIA thermoquad or 2 barrel..
 
Take each one for a drive.Buy the one that runs better.But what I would do is buy the car with the best body and interior.You can do alittle upgrading to the 383 or the 400 and really wake the motor up.
 
68383GTS said:
Take each one for a drive.Buy the one that runs better.But what I would do is buy the car with the best body and interior.You can do alittle upgrading to the 383 or the 400 and really wake the motor up.
Click to expand...

the engines are easy to fix or upgrade...yes..take the one with the best body and interior....or best over all condition
 
MyBlueCuda said:
I've had both motors. The 400 is a dog. It was basically a de-tuned motor to keep the government happy.
I had a 1964 Plymouth Sports Fury with a 383 4bbl automatic that ran high 14:00 in the quarter that was completely stock.
Versus a 1972 Dodge Charger with a 400 Magnum automatic that ran 17:00 in the quarter bone stock.
The 400 Magnum has a real crappy intake manifold. It has an internally built in E.G.R. valve that hurts performance. On top of that is the Thermo-Bog carburetor! Never really was too impressed with that carb.
If you can find a rebuildable 60's 383 with small chamber heads I think it would be the way to go. The 400 may have a larger bore but I'd bet on my old 383 every time.
Click to expand...

Then you had a BAD running 400, I've seen 1st. hand stock 400 long blocks with just bolt-ons & a good tune run great, i installed one in a 74 duster that came out of a 75 newport, nothing was done to it other then HP manifolds & a single exhaust, yes i said single, the engine had a very worn out timing chain, stock intake & a 2 barr., stock converter & 2.91 gears, it would fry the tire through all gears.
 
Drache said:
bigger isn't always better, 383


You'll find more parts and better parts available for the 383.
Click to expand...

I'm sitting here trying to think of speed parts that fit a 383 but not a 400. All I come up with is pistons. Same heads,rods,exhaust,intakes,cam,distributor,etc,etc,etc. As stated,buy the best car then build a good motor for it.
 
MyBlueCuda said:
I've had both motors. The 400 is a dog. It was basically a de-tuned motor to keep the government happy.
I had a 1964 Plymouth Sports Fury with a 383 4bbl automatic that ran high 14:00 in the quarter that was completely stock.
Versus a 1972 Dodge Charger with a 400 Magnum automatic that ran 17:00 in the quarter bone stock.
The 400 Magnum has a real crappy intake manifold. It has an internally built in E.G.R. valve that hurts performance. On top of that is the Thermo-Bog carburetor! Never really was too impressed with that carb.
If you can find a rebuildable 60's 383 with small chamber heads I think it would be the way to go. The 400 may have a larger bore but I'd bet on my old 383 every time.
Click to expand...

What was your gear ratio and tire size on that car?
I took an entire drive train out of a '78 Cordoba and into my Magnum. A "P" code 400, 727 & it's 3.23 rear to low 15's and I'm thinking not to shabby for a emissions year engine with over 300,000 miles on it.

OH, that EGR gas is inert and effects performance only on part throttle operation. At W.O.T. the valve closes and there is absoultely ZERO exhaust gas going into the engine.

The T.Q. carb as delivered ('79) is lean and a poor performance choice until modified for such use.

I'm thinking that a 400 in a Duster would more likely NOT be a stock engine on the inside.
 
400-bigger bore
383-smaller bore

if they are stock bottom ends, the 383 has better cylinder pressure to start.

if not, go with the 400/bigger bore.

they are the same size.
 
OH, I'm planning on moving that engine drive train into a 70's Duster later. Well, not the 9-1/4, I have an 8-3/4 for that Duster. Hummmm, I wonder what a otherwise bone stock 400 will do. I have B body headers for the swap and on the engine, a Holley Street Dominator with a electric choke 800 cfm T.Q..

It may be awhile, but I'll letcha all know. I don't think it'll be great, but at a few hundred pounds lighter than a late B body.....
 
I wounder if I can squeezzzeee out an 11 sec E.T. from one of these smog pig's with bolt on's and a cam? A set of 4.30's to start and a converter to match I think! LOL!
 
Biggest problem with stock block 400's is that the compression was only 8.5 (or slightly lower) with the piston .075-.080" below deck for 200-230HP. When compared to the "stock block" 69-383 you get 10 to 1 with a piston proud of the block by .021" and 335HP. Big difference, this is why I'm more drawn to 383 as the start point.
 
MyBlueCuda said:
I've had both motors. The 400 is a dog. It was basically a de-tuned motor to keep the government happy.
I had a 1964 Plymouth Sports Fury with a 383 4bbl automatic that ran high 14:00 in the quarter that was completely stock.
Versus a 1972 Dodge Charger with a 400 Magnum automatic that ran 17:00 in the quarter bone stock.
The 400 Magnum has a real crappy intake manifold. It has an internally built in E.G.R. valve that hurts performance. On top of that is the Thermo-Bog carburetor! Never really was too impressed with that carb.
If you can find a rebuildable 60's 383 with small chamber heads I think it would be the way to go. The 400 may have a larger bore but I'd bet on my old 383 every time.
Click to expand...

That Charger was probably 500-600 pounds heavier than the Fury in addition to all the emissions crap and low compression. That's not really a good comparison. This Duster is obviously not a factory correct, stock restoration, right? Who runs the stock intake manifold anyway?

The only real downside to the 400 is that it probably has a cast crank. Depending on what the OP has planned for this car, it may or may not be a problem. A set of closed chamber heads will bump the compression up nicely for street use.
 
rumblefish360 said:
If your reffering to my duster, I will tell you it was stock, "bone stock" with a 2brr., money was tight & i got the Newport for nothing, so i dropped it in, the Newport manifolds wouldn't fit, got a set of HP manifolds on a trade, this was back in 92, the car had lots of power & was fun to drive, This was down in Corpus Christi Tx., so Alt. was on my side seeing i was no more then 50ft. above sea level, i'm sure that helped alot, either way, when it came to the Duster i put together, it had a "STOCK" 400. I have also seen a couple over the years with stock 400 long blocks with exception of a cam (ok stock rotateing assembly/heads) & bolt-ons/gears/stall, they ran surprizeingly good.
Click to expand...
 
Joe, 1st up, I thought there was an issue with the "Quote" in your post. I tried to fix it. Nothing else was modified. Sorry about that.

2nd I wasn't refurin to you or your car in anyway shape or form. Though I certainly understand a tight money issue. Now, IF ya can remember, what did the other lo-comp 400 combo cars ran, I'd like to know. I'll also have to go this route for a while.

Should things go well, perhaps I'll add a hair drier blower to it. First it'll be a set of 4.30's and I'm thinking a 29 inch tire. Future cam unknown at this point. 296/.557 purple? IDK
 
I say go with the cubes. The 400 has some nice KB pistons available that can get compression around 10:1. The 400 is kinda like a big block 340. Short stroke and a big bore. Get a good balance job on it and a high quality ballancer and you can rev the snot outta one. And at 4.342" that bore will produce a lot of power.
 
rumblefish360 said:
Joe, 1st up, I thought there was an issue with the "Quote" in your post. I tried to fix it. Nothing else was modified. Sorry about that.

2nd I wasn't refurin to you or your car in anyway shape or form. Though I certainly understand a tight money issue. Now, IF ya can remember, what did the other lo-comp 400 combo cars ran, I'd like to know. I'll also have to go this route for a while.

Should things go well, perhaps I'll add a hair drier blower to it. First it'll be a set of 4.30's and I'm thinking a 29 inch tire. Future cam unknown at this point. 296/.557 purple? IDK
Click to expand...

I know for sure one was in the low 13s, & this was at 3700ft. Alt., they do have the potential to run strong with a stock bottom end, The main reason i think we don't "see" them being much of a perf. is 1st., we just stroke them, 2nd., we go with a 440, or 3rd., we will rip them down & install higher compression pistons.

If you are close to see level, & you run those gears, install a decent cam & a good 36-3800 stall along with bolt-ons, you'll be amazed how quick they can run, even though the compression is a bit low, They still have a "huge" bore & short stroke.

A friend of mine's mom had a 76 Cordoba with the 400, don't remember if it was lean burn or not, He wanted to see how it ran, so he took the keys from his mom while she was shopping at the mall & we ran it around the parking lot, it had some balls let me tell ya, sure got my attention, he never knew how good it ran because his mom always drove like a "granny". But after discovering what was under the hood, he was bound & determined to take it for a spin.
 
As a heads up-Back in the day (ya I am that old) you could get the 340 sixpack to run harder that a 383 HP. It was lighter and the car would handle far better with the 340 as well- a win-win. The 400 was a smog motor to replace a 383/440 with and the stock ones have a cast crank. If you are using a 440 crank in a 400 block why don't you just bore out a 440? FYI the 383/413/440 motor home engines had a higher nickel content and the "motor home" heads with the extra water jackets around the spark plugs to help with any pinging problems.
 
ehhhh....lots of 400s came with steel cranks. I had one.
 
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