As I am taking the 440 out I am learning alot about it, One thing is that my 440 is a 78 model and a RB....Now I read somewhere that RB was for Raised Block what does that mean and is that good?

 

ray -

All 440's and 426 engines are of a Raised Block (RB) design referring to the deck height, as compared to the 383s and 400 which were considered low blocks.

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

Archer

 

Yep! The 383s were just B.

 

It is referenced to the distance between the crank centerline and the top/deck surface. The RB is about an inch higher than the B or RB raised block

 

Not quite true. In the late '50'searly '60's there also was a 383 RB engine. I don't think you are likely to run into them.

"B" engines are the early 350, 361, 383, 400.

"RB" engines were the early 350, an RB 361 the oddball 383 RB, and the more common 413, 426, 440

The thing you need to be careful of when buying used parts is the pushrods, distributor and intake/ valley pan, and of course internal parts on the bottom end.

Pan, heads, etc, interchange

B engines:

http://www.allpar.com/mopar/b-engines.html

RB engines

http://www.allpar.com/mopar/383.html

 

The raised block allows for a longer stroke.
Where the B 383 can turn 7000 rpm all day with a shorter stroke, the RB would make more torque with it's longer stroke.
each block served it's purpose.