I'd recommend taking the size 33's. We found that this batch of heavyweights sewed down a little small, so a 33 is a true 33 to 33.25" in the waist as opposed to our usual vanity sizing of 1" from tagged size. That being said, this denim stretches more than our flagship 14.5oz so you'll get a good 1.5" of stretch over the first month of wear - so while they'll be snug at first, you can get the tagged 33 to a 34.5" no problem. Hope this helps!
11/16/14 at 2:18pm