I am planning on building the exact same 318-400hp junkyard jewel that Hot Rod built a few years back. link: http://www.hotrod.com/howto/113_0304_318_small_block_build/index.html
I had also read another 318 build that mopar muscle built using off the shelf parts and magnum heads. In the article from the mopar muscle build they mentioned that the early rods from the 318 weren't as strong as the later rods. I've read How to Hot Rod Mopar small blocks and it never mentions that the rods from the early 318's are weaker but it does mention that the early rods have full floating piston pins which I would rather have if the strength between the early rods and later rods are equal. As you have probably figured out I'm too cheap to buy anything aftermarket otherwise I'd probably be building a 340. Any help would be greatly appreciated.

The early 318 rods were slightly lighter but I know several guys running them on the dirt track because they are a little lighter.

I have a set of (7) floating pin 318 rods, casting #2406782. I bought them as spares, hence the incomplete set........they are clean, and in great shape. The rod 3rd from the left is copper coated, that's not rust. Let me know if you are interested, just PM me.

have the dirt track guys ever broken a rod with the floating pin type?

Not rreally that you would attribute to using the lighter rods. Hell they can break anything.

There is always that possiblity, I guess the question you really need to ask yourself is how much you want to abuse this little engine? If you are really trying to get big block power out of it, then maybe you should build a big block instead..........

Not really interested in big blocks. I like the idea of building a fast car for practically nothing. That's why I've chosen the 318 they're practically giving them away I'm just trying to make sure that I'm not going to throw a rod because I chose the floating pin rods over the pressed pin rods.

The rods will be the least of your worries. You won't put the abuse on it in years that they do in 1 night. They ain't pushing 318 size pistons around either. They are using 360's.