bOb shingler
Well-Known Member
consider this, you just want to toss a bb in your hotrod and go. grab the 400 it has the harden valve seats for todays gas. you don't even have to take it apart just scrub the sucker down, paint it and stuff it in.
383 or 400 ?
- Thread starter jtkaaa07
- Start date
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383Scampman
Well-Known Member
A 400 with a .020 overbore is the same as a standard bore 440. If I had both a 383 AND a 400 I would put the 383 crank (forged) and rods in the 400 with forged lightweight magnum pistons from a .020" or .030" 440. TRW makes them. This yields 406" with a .020" over or 410-411" with a .030" over. It's much easier to install a low deck 383/400 in an a-body than a 440. Advantages abound. Later, Tom:cheers:
451Cuda
Well-Known Member
I don't even collect 440 blocks anymore, all my builds will be 400 based. When I get to the point of building a big cube RB it will be an aftermarket 4.5 bore block.
Excuse me? Lets clear this up once and for all. A standard 400 bore is 4.342". A standard 440 bore is 4.320". So, how in the hell can a .020 over 400 have the same bore as a standard 440 when it's already bigger to begin with? Some of yall really need math lessons. Bad. The 400 has the biggest bore of ALL the big blocks. Period.
I love these either or threads and the myths they present.lol
Magnumforce1987
Mexican Hillbilly!!!
x2!!!
We bored 40 over and put in TRW L2388f-60 which raised the compression ratio from 7.crap to 9.3. Abacus included
If your still on the fence go to 440 source website and under information they will give you an education on the different 400 blocks and casting webbing etc. Very informative.
jtkaaa07
BossMan
Interesting, I never knew the 400 had that big of bore, do they just make a higher compression piston seeing that seems to be the only downfall to the 400? oh, and of course the heads too!
Jcox68rt
Member
I have the 451 in my 68 charger rt... It happens to be a block from 72. It's a stroked 400 with 440 crank and 440 rods and Ross pistons. Dropped some ported and polished 906 heads with hardened seats and three angle valve job from a 440 my old boss was getting rid of in lieu of aluminum heads. Final compression came in at 10.1 or 10.2:1 (can't remember off top of my head) it runs on 91 octane pump gas and absolutely screams! Torquey low deck sleeper that confuses people when they look under the hood. I love it! I have a 73 400 motor & 727 I'm contemplating dropping in my /6 valiant if I come across a cheap/reasonable 8.75 locally... You will never be disappointed with a 451 build, and if you source the parts yourself and not get a kit you can build it with some budget in mind. Just my .02
jtkaaa07
BossMan
Cool, so are the Ross pistons for a 400 or 440? I have all the other stuff from a 440 available, I didn't realize I could use 440 crank and rods. I have a buddy with a 451 in his car, but I thought that was a 440 based motor.
440outlawdart
Well-Known Member
I would use the 400 and go to 4.375 bore,and 400 will have a stonger bottom end
moper
Well-Known Member
The only way a 440 piston can be used in a 400 is if you put the same stroke crank in it too. Hence the 451, 470, 496, 505 deals that use the same pistons rods and strokes.
If it was me I'd run the 383 and either keep or sell the 400 on. The 400s worth something - the 383 isn't.
If it was me I'd run the 383 and either keep or sell the 400 on. The 400s worth something - the 383 isn't.
69conv and I have mentioned how a 440 piston in a 400 is possible. A .060 over 72-78 type replacement 440 piston in a .040 over 400 block. At one time it was a fairly economical way to raise compression in a 400 back before the KB hypers were available. I would get both engines, use the 383, and save your pennies to build a stroked 400 based engine later.
Jim Lusk
Well-Known Member
So what happens if you put those .060 over 440 slugs in a .040 over 400 using the 400 crank?
Somebody already answered your question...
Somebody already answered your question...
Hey a 452 head was on lots of 400s , 452 is a good head for the stroker build
So that's it?
Simply bore a 400 block .040, and get, say 1977 .060 440 pistons.
Done and 9.3:1 411 CID?
Dang, talk about a best kept secret.....
moper
Well-Known Member
Looking at the various offerings - you have to be careful on which 440 pistons you want to use. A stock 440 piston is shorter than a stock 400 piston by about .065". That would make the 400 even lower compression than a factory 400 piston would. Using the hyper KB237 - those are much taller, and if you used that with the factory 400 crank and rod it would stick out of the deck over .100". The L2276 TRW will stick up about .025" give or take based on a blueprint deck height. The good news is they're usually taller than blueprint.
So - while it might work I'd suggest you do your homework. It's not like any 440 piston will work well.
moparlover
Well-Known Member
if the 383 is in running condition, just run it. if you are building, do the 400 block with forged 440 crank deal. 451 > 383 if you are spending machine shop money. (i.e. i wouldnt spend money to machine / refit a 383 unless it's for a matching numbers show car rebuild)
Louc60
Member
A 383 is still a good choice.I just finished a change over of a mildly built 383 to a slightly more radical 383 with .060 overbore into a real H code 67 Dart.The motor we pulled was a strong performer but my friend wanted a little more punch.The new one is 425/450 hp versus 350/375 on the motor pulled.The motor is for sale.Here's a shot of the pulled motor.I've got a DVD of the car running last year which shows the car in action on the street.
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BTW this car was featured in a article in Hemming's Muscle Car earlier this year.
BTW this car was featured in a article in Hemming's Muscle Car earlier this year.
Louc60
Member
Here's a shot at the Chrysler Museum show a couple weeks ago two days after completing the engine switch.
My 76 400 block came with the 452 heads. A little port matching and bowl blending which you can do yourself and you got a screamin build. BTW pay attention to the compression height on your 440 piston choice, that's where the magics at.
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