Yes is my quick answer.

We went 6.13 with a pump gas 512/440 without a lot of effort, and our race gas 400/512 runs about the same ET after lots of effort.....We suspect its the longer rods that allows the 440/512 to pull harder on top, but that's just a guess. It also took us a while to get the little 400/512 to mph the same. And you have to remember, its got smaller journals and weighs less, so where is the improvement?

I did learn, the 400/512 intake seems a bit more restrictive than the 440 based intake. I gained a bunch of ET when I ported the intake. So, it might be a plenum thing. We have debated this around the shop for a while as the small journal and light weight B combo should be faster than the RB, but it has not turned out that way for us. Same carb, same heads, same cam, same headers, same car.

So it begs the question, what happens if we go to a high compression 440 based unit of the next size up?