I know head bolt and cam bearing difference. Any thing else different? Which one is better for build?

 

I've heard 05+ have better rods as well.

 

^^Thats what everyone claims. Allegedly the 05+ has the LS2 style rods which are much better. I believe the timing chain was also beefed up to the LS2 style.

 

04+ will have LS2 style rods and lifter trays.

If you're planning to use aftermarket rods, then I don't think there is any meaningful difference. Heck, even the old Gen 3 rods are probably strong enough for most builds.

99-00 LQ4 will have iron heads and long flange crank.