Mopar 440 Engine, how big can I go?

I'll see if I can find a couple pics to show you how to tell......

This is a 440 or RB block....RB blocks were used as 413, 440, 426 Wedge and 426 Hemi.



You can see a rectangular flat pad on the front of the engine just to the right of the distributor hole in the block...it's level with the mounting flange for the intake valley pan.

Now only RB blocks have this "pad" all other big block mopar motors...The B deck's...350, 361, 383, 400...will "not" have this pad....see pic...



You can see that it is missing that pad in this pic.

So look for that pad if you got one then it's an RB motor...missing B motor.