Let's bring this back from the dead! For future readers of course. Being that I'm in this very situation, trying to decide between an LA or poly, I figured I'd chime in. I've researched both engines and worked with both engines my entire life. I like both engines. However, there are many practical advantages to ditching the poly. One, the lack of an aftermarket, two, the heads do not flow as well as some make it seem. The poly head is plagued by poorly designed exhaust ports. They have excellent intake ports. But the exhaust is really restricted. Which is the exact opposite of the LA 318. The LA has restricted intake ports but really good exhaust ports. Though, magnum heads are better than both. Speaking of exhaust, headers for the poly are only available from tti and are 725 bucks! You could take that 725 and buy headers an intake and a carb or cam for an LA. If you read around online you'll see several articles laying out 400 horse LA 318's built from mostly factory parts. You will not see that with the poly. Ever. So I vote LA. The poly is cool for cruising around and does have potential. But for the money, the LA, and especially the magnum, rocks the polys world. I'd also like to note the hp rating for the poly is usually a gross rating. The newer LA and magnum is net.
