Livingston,
Assuming that you are burning Gas or light oil and this burner fires with 100% air through the burner and you are firing with 10 to 20% excess air - this should normally not be a problem for a few percent increase in capacity. That is if you are firing into the same system. You should not see any flame problems or decrease in burner life.
Note you may see a slight increase in air pressure drop you are putting more into the burner so you will need to push it a little harder. You will want to verify that your combustion air fan is properly sized for the added capacity - flow and pressure. Using 20% excess air your fan will need to be capable for 9586 scfm.
If the units vary then you may need to evaluate the chamber size you will be firing into to accomodate flame dimensions, draft fan capacity etc - you need to evaluate the whole system to see if it will work.
More details wouls help - Burner make and model, fuels fired, type of unit you will be firing into - is this a Low NOx application? There are a lot of variables.
Good Luck!
Combustor