Well O.K then.The 400 block is also lighter than the 440.
The 451 rotating assembly will be significantly lighter than the 440's. Everything is lighter. If you really wanna step it up offset grind the 440 rod journals to 3.92 stroke and use a bb chevy rod with a .990 piston pin. There is a huge savings on piston weight building a 451 this way. This relates to a quick revving big block mopar that will e.t well and give great 60' times.
It becomes childs play to make 650 h.p at this juncture.
