400 vs 440

[sixty6charger]

A second question is this, I have heard you will run into troubles with headers hitting other things in the engine bay and so on with the shorter block of the 400 as opposed to the 440.  Is there any truth to this and if so what all kind of problems will I run into?  Its a 73 Charger and this is the factory block.

Well, I have a 440 in my car (1966) and the headers are a pain in the a$$ when putting the engine in and taking out! Chances are you'll need to dimple them to give some clearance. If you have power steering it makes it worse than not having it, but I'll assume you have it. Don't know if a 400 would make a difference. I'm incline to say no.

[andyf]

Well headers can be a big pain so that is one thing to research before you make a decision.  Some vendors have low deck headers (383, 400) and other vendors have RB headers (440 blocks).

The other option is to run HP manifolds and forget the headers.  I've run HP manifolds on stroker motors before for street cars and it works just fine.  My last combination (low deck 466 with Eddy heads) made more RWHP than a new Viper yet was nice and quiet with the manifolds and ran on pump gas.

[MOPARHOUND!]

So basically what you guys are saying is that for less than it would cost, to buy and rebuild a 440...  I could take my original 400 block and build it, and it would be stronger, more powerful, more durable, and get better gas mileage than the 440? 

That is not what I am saying.  I repeat, keep it simple, and reliable, build a 440.

Pros and cons?  The short version of the 451 cons:

B main crank spec's are inferior to RB main crank spec's (look 'em up).  IMO, the used cut down 440 crank in a B engine will fail before the  440 block main saddles will fail.  Buy a new crank and cut it down?$$$  Anyone making over 600hp with a B engine?  If so, for how long?  The difference in reduced drag is nearly inconsequential in a street engine, and in a race engine you would gain what, .0001 off the elapsed time?

B intakes are inferior to RB intakes.  Relatively speaking, poor plenum volume for the cid being fed, tunnel ram and cut the hood?$$$, stage VI heads, to allow use of RB intake?$$$.

B block's cylinders distort more than RB block's cylinders (theory says otherwise, however real world experience proves it).  RB wins the longevity race on this count.

B block 451 requires a piston/wrist pin spec. with a greater tendency to rock in the bore than the RB, greater risk of oil consumption/blow by, longevity is decreased.  More than one report of premature oil burning.

451's have an application, in space limited A-body racecars, making 1/4 mile passes one at a time, and being torn down periodically. 

Can you build a moderate 451 B engine for street driving on weekends and it survive?  Yes.  I wouldn't, better alternatives.

Besides, you can build the the 440 even bigger at a later date, if funds allow.

(By the way, RPM stands for Ruins Peoples Motors.)

[firefighter3931]

So basically what you guys are saying is that for less than it would cost, to buy and rebuild a 440...  I could take my original 400 block and build it, and it would be stronger, more powerful, more durable, and get better gas mileage than the 440? 

That is not what I am saying.  I repeat, keep it simple, and reliable, build a 440.

Pros and cons?  The short version of the 451 cons:

B main crank spec's are inferior to RB main crank spec's (look 'em up).  IMO, the used cut down 440 crank in a B engine will fail before the  440 block main saddles will fail.  Buy a new crank and cut it down?$$$  Anyone making over 600hp with a B engine?  If so, for how long?  The difference in reduced drag is nearly inconsequential in a street engine, and in a race engine you would gain what, .0001 off the elapsed time?

B intakes are inferior to RB intakes.  Relatively speaking, poor plenum volume for the cid being fed, tunnel ram and cut the hood?$$$, stage VI heads, to allow use of RB intake?$$$.

B block's cylinders distort more than RB block's cylinders (theory says otherwise, however real world experience proves it).  RB wins the longevity race on this count.

B block 451 requires a piston/wrist pin spec. with a greater tendency to rock in the bore than the RB, greater risk of oil consumption/blow by, longevity is decreased.  More than one report of premature oil burning.

451's have an application, in space limited A-body racecars, making 1/4 mile passes one at a time, and being torn down periodically. 

Can you build a moderate 451 B engine for street driving on weekends and it survive?  Yes.  I wouldn't, better alternatives.

Besides, you can build the the 440 even bigger at a later date, if funds allow.

(By the way, RPM stands for Ruins Peoples Motors.)

Well said Hound  100% !

B-engines for racing....RB engines for street/strip. Big ole Chargers have tons of room in the engine bay.....no need to squeeze a small engine in there.  Lots of header choices that fit the chassis w/o clearance issues. A 440 just looks "right' in there.

Ron

[my73charger]

As for the headers situation.  I have had both blocks hooked up to headers.  They are very tight but do fit with very little tweaking.  I have used the same headers with both blocks.  Hedman Elite headers.  I have power steering and had to put one dimple in for that but relatively little trouble.  Other than that I have had no trouble with headers.  I spent $4500 on building my 440.  That inlcuded buying the block, having everything balanced, new damper, bored over .060 Speed Pro forged pistons 10.3 to 1 compression, comp cam.  Had the stock heads worked over.  Had a machine shop do everything including the complete assembly less the bolt ons.