400 big block

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Mark Benson

1975DodgeDartSwinger318
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Can any of you tell me the HP/Torque rating for my 73' 400 BB four barrel? It came out of a 73' Sattlelite (with a RoadRunner package). Also can it be built to be pretty stout at the dragstrip? Any information would be appreciated! Thanks!
 
The word on the street is that they make one great STROKER!!!! I am sure someone alse will chime in with the details.....
 
I don't know what the HP/torque ratings were but they were not impressive. On to the other part of your question. The 400 blocks are a stout piece. The old way to hop them up was to stick a steel 440 crank in them and come up with a 451. With the proper pistons,cam and head work, you can get some real monster numbers this way and have a very strong block. I'm not sure that the cylinder walls are any thicker than a 440's but the webbing around the mains is much beefier making it a very strong block. I'm sure some of the more knowledgable guy's like BJR Racing and moper can fill you in on this setup.

Jack
 
Mark,
Call me and I can answer most all your questions, 770-443-8874.

If you want I can call you as it doesn't cost me anything. I just need your # , you can PM me if you don't want everyone to know your #.
 
my buddy has a full steel duster.stoked a 400 to 451.it is running a best of 9.20 on the motor.no nos.pure muscle.
 
Yup Mark the 451's the way to go. Stock the 400 low comp. was a dog at, I think, 225 HP. I'm building a stroked 400 this winter, got the stripped block in the garage, and I'll probably be calling BJR for pointers.

Terry
 
The 400 is basically a big block 340. Bigger bore, but a stroke of a 383. They can run very well without going bigger. But... They have the best main webbing of any mopar big block. So, with the availability of kits, and the fact taht most of the operations are the same...building bigger is easy. Teh 451 is a greta all around package. The 470 is also very nice, and can run well on factory type iron heads. Bigger than that, the costs go up with better head choices. In any case, a real nice 400 build is a 383 crank, forged pistons, stock rods, and a cam that will make peak torque in the 4Krpm range. Then it will rev nice too. The crank is the weakest link. And a 383 forged is a drop in.
 
Like MoPer said.
The 400 with it's stock short throw crank can be real good at the street or strip. You have to treat it like a small block. The short stroke crank @ 3.38 will rev real fast and high. They are cast in the 400's so a fordged 383 part would be better for hi horse applications.

Theres nothing wrong with staying @ 400 cubes plus any overbore. KB makes a piston(s) for the 400 with the stock stroke. They cost more than other pistons because of low demand. But in the overall picture, it keeps costs down. No extra crank to purchase like in a stroker if you stay with the cast crank which will hold some good power.
Or extra money for mallory metal in balanceing the assembly, which should be balanced with new pistons overbored or not.

The 383 back in the day was a street terror and the 400 with it's 17 cube advantage will perform just like the 383 did back in the day.

MoPar Muscle mag did a 400 build up with some basic part. Dual plane, 750 Holley, headers and a cam (Smallish) into a rebuilt short block to come up with 400 HP.
 
I am also very excited to read about this 451 build. That is the way to go since I can come up with most of everything I will need but the shop work, our little town is very limited. Will the 906(I think)440 heads bolt anto the 400 block? I have access to a nice set of those.
 
Vic Storm said:
I am also very excited to read about this 451 build. That is the way to go since I can come up with most of everything I will need but the shop work, our little town is very limited. Will the 906(I think)440 heads bolt anto the 400 block? I have access to a nice set of those.
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Vic, the heads used on the 383, 400 and 440 were all the same. In other words you could use the 906's and 452's on all three engines along with all the BB heads. If you're going to use the 906's I'd recommend getting hardened valve seats installed (for the no lead fuel) and by the way most of the 452 came with hardened seats also the 906's and 452's had some of the best flow numbers for stock heads. Here's an article on the BB heads that might interest you. Opps sorry it's on my home computer and I'm on the road.

Terry
 
Opps sorry it's on my home computer and I'm on the road.
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Bwa ha hah a. I do the same crap with the lap top from time to time.

The 452's, from what I have read, port out better than the 906's.
The 906 is a slight better than the 452 as cast.
 
Thanks, that is very interesting to me. So the combination you use will also determine which camshaft you choose right? I have been wanting to use one of those Xstreme comp cam kits, say a 292/506 hyd. Would that be too much cam for a stock block 400 with say ported 452 heads with single plane (Torker type) high rise and four barrel carb(780 d/f D/P) using the 440 crank set up?
 
Check out 440 sorce.com they have good stroker kits at resonable prices and ive heard nothing but good about there stuff.They have 400/451 400/470 400/500 and 400/512 kits i believe.there kits are all around $1300 or so.
 
ace26 said:
Check out 440 sorce.com they have good stroker kits at resonable prices and ive heard nothing but good about there stuff.They have 400/451 400/470 400/500 and 400/512 kits i believe.there kits are all around $1300 or so.
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exactly, its about $1500 if you want the rotating assembly ballanced. bolt on a set of ported cast iron heads do a little ignition and oiling upgrade and seeing 550hp is not out of line. I talked to the guys at the 440 source back when i wanted to put a big block in my duster, they know what they're doing, great prices.
 
thanson_mopar said:
exactly, its about $1500 if you want the rotating assembly ballanced. bolt on a set of ported cast iron heads do a little ignition and oiling upgrade and seeing 550hp is not out of line. I talked to the guys at the 440 source back when i wanted to put a big block in my duster, they know what they're doing, great prices.
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To get that power, it's much more than that. Brandon has decent product, and very good pricing. But there's a lot more to it than tightening a few bolts and firing it. The dead simplest is the 440Source B wedge 3.75 crank, rods, and pistons in a 400 block. Then it's a bolt in "build like a factory engine" deal and the cost is similar. The 3.915 stroke isnt that bad. Any bigger than that, and things get harder and more expensive in B wedge block.
 
moper said:
To get that power, it's much more than that. Brandon has decent product, and very good pricing. But there's a lot more to it than tightening a few bolts and firing it. The dead simplest is the 440Source B wedge 3.75 crank, rods, and pistons in a 400 block. Then it's a bolt in "build like a factory engine" deal and the cost is similar. The 3.915 stroke isnt that bad. Any bigger than that, and things get harder and more expensive in B wedge block.
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Not impossible, and yes there is more to it than bolting on a set of heads, i guess i wasnt going into detail about it. the 451 is great but for the same price you could upgrade to a size or two bigger. The main thing is doing a little machine work in the block so that theres no clearance issues with the crank(unless you use the 3.75 inch crank, this will drop right in as moper said). It can be done, ive seen it, with a street driven car with reliable (as a big block can be) horsepower. If i remember correctly it was apr. 556 horsepower to the flywheel. I know for sure that all these diffrent stroker kits from 440 source are the same price, wheather you want a 451 or a 512
 
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