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[Ranger Max]

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[Nacho-RT74]

I think you have a limit to over bore a 383 like a 400... I have read 400 engine does it have bigger cilinder walls. For sure 400 it has stronger/reinforcement mains arears. 400 is a stronger engine.

somebody posted on the old D-C board pics with what makes difference a 400 from the rest.

[RD]

383 vs. 400

bore size

ok, next question... hehe j/k

383's cannot be bored out to a 400

383 = 4.25 bore
400=4.34 bore (largest bore of all b/rb engines)

383 other than that, the blocks are identical and every part can interchange.  Now if you are talking about a RB383, that is a totally different story.

[RD]

Here, let me try to explain this better.  the blocks are not identical based on the bore size, but every part that attaches to the two blocks (i.e. heads, water pump, etc.) can be swapped between the two engines.

The only difference between the two engines is the stock oem bore size based upon the casting method/mould.  383's were cast and bored and honed to a stock 4.25 bore.  400's were cast and bored and honed to a stock 4.34 bore.

If a mopar engine can safely only go to .060 by some standards, then 4.25 + .06 = 4.31.  Hence, it will not be able to be "safely" bored out to a 400's stock bore size.

The two castings/moulds are different only in this regard, which is bore size.  Other than that, everything else on the block is identical.

[cudaken]

 Nacho, I have never heard the 400 had a stronger/reinforcement mains arears. Think your are wrong on that part.

RD is right as usual.

Even tho the 400 cast crank is strong, 383 steel crank is stroger. It will fit a 400 block if you are looking for over 450 HP.

                                  Cuda Ken

[ScottW]

Go here:

http://www.440source.com/blockinfo.htm

Lots of information on blocks with detail & pictures.

[Nacho-RT74]

somebody posted pics with that info on the old board showing the stronger areas at main berings ( and other reinforcements all along the block ), AND SCOTT supported me with that link... soooo

I WIIIIN... 


LOL.

[Chryco Psycho]

I agree with Natcho , the 400 is a stronger block than the 383 

[cudaken]

 Sorry Nacho, but I did learn something. Never head that before.


                                             Cuda Ken

[471_Magnum]

I agree with Natcho , the 400 is a stronger block than the 383

Not necessarily. Only the "cold weather blocks" aka 230 castings have the meaty bottom end. These were generally cast late in '71 for the '72 model year. Other 400s are pretty much the same as 383s, but that doesn't make them bad by any means.

[RD]

I agree with Natcho , the 400 is a stronger block than the 383

Not necessarily. Only the "cold weather blocks" aka 230 castings have the meaty bottom end. These were generally cast late in '71 for the '72 model year. Other 400s are pretty much the same as 383s, but that doesn't make them bad by any means.

true, and that 230 casting with the reinforced mains was cast only from mid to late sept to Oct.17 if I remember correctly.  It was a 1 month only run, then they went with a less intensive casting to save cost.