<font color="blue"> in your opinion does the plow attached to the loader arms put too much lateral stress on the loader arms</font>
The Curtis blade has a trip that flips the blade when load is to great. Mine is 5 years old with no problems. Other have said that they heard of loader frames being bent by front blades. But I have not heard of it happening to a Curtis blade.
<font color="blue"> would the Curtis plow fit on the loader arms of an
L3400 </font>
Curtis makes an adapter that will fit a QA. Here is a link to their site.
Click Here
If I was purchasing a
L3400. It would order it with a aftermarket QA and Bucket. You will also need at least one remote.
The
B3030 is a different tractor. I would recommend Kubota's Quick Coupler. Then modify mounting brackets that Curtis supplies to fit. That is what I did. On remote is also needed.
Here is a link to
B3030 Candies.
Click Here Which shows the Quick Coupler.