Why does the shimano stradic 4000 weight 2.7 ounces more than the similiarly priced daiwa tierra 3000?, both have the same line capacity. Is the shimano built stronger?. This seems like a lot of weight difference for reels in the same price range. I want the lighter reel, but not if it means sacrificing durability.

If you're using it for bass fishing, the 2500 series in either reel will give you plenty of capacity.  In that size, there is only 0.1 oz difference.  I'm not sure of the reason for your original question, but I suspect that the Daiwa is a smaller bodied reel with a large capacity spool.

Because the Stradic 4000 is a monster huge reel all over while the Daiwa Tierra 3000 is a Tierra 2500 size body with a bigger spool.

Because the Stradic 4000 is a monster huge reel all over while the Daiwa Tierra 3000 is a Tierra 2500 size body with a bigger spool.

That's what I meant.  Raul said it better.