Big Block vs Poly

Over the past several issues Chrysler Power mag has really been trying to revive the Poly Engines. I have been following along and think that the articles have been interesting. At the very least it is different.

My goal for my 1968 Barracuda is around 550hp. What I wanted to do was build a 400 block with a 440 crank, using as much aluminum components to get the weight down. So aluminum intake, water pump housing, heads. Also headers to help get the weight down.

The Poly motor. Looks like a LA or Magnum block could be modified for the Poly heads to work. To get to the power level I would like a 318 or 360 would have to have a 4" crank. So we would be looking at 390c.i. using the 318 block or 408c.i. with the 360 block. But I'm stuck using cast iron heads. I'm not sure how much the poly heads weight, but would it be lighter than my proposed BB above?

What do you think Big Block or Stroked Poly? The Poly would be different.

I guess what it comes down to is weight and power. Would the LA with Poly heads and aluminum intake, be lighter than 400/440 with aluminum intake, water pump housing, and heads?

The 550hp goal would probably be maxing out what the proposed Poly motor would be capable of making. While the 400/440 could still have some hp left in it? Am I correct in what I'm thinking there?

The reason I asked this now is I found a set of Poly heads in the Junk Yard. So if I do go the Poly route I can start collecting some parts.