The R blocks are heavier yet and 4000$. The Poly heads are 10 pounds heavier each bare and the block is 23 pounds heavier than an La before it's bored to 4". The main webs are more solid not hollowed on one side and you can beef the bottom end up to hold 750 hp safe that the La can't take. If the poly heads wont fit I'll adapt the poly block to an La head and then supercharge it down the road. That's why I don't want to run a 340 or 360. They won't take the power I'm going to run as well. I can live with the extra weight if it will take the power.
