Changing Field Lengths

Does anybody know if there is a way to change the legth of digits for a field?  For example, in the budgeted contract, or the payment requisition, my item numbers can extend to 12 digits, but the fields are only 10.  We are using CM 14.

Another question on a similar note...Is there anyway to lock the item number when generating a requisition from a budgeted contract?  We use the DOT's (or municipality's) item number when we create the budgeted contract, then generate the requisiton and CM automatically renumbers them.  Then we have to go through, sometimes 100 items and change all the number back to the item number!  Too much double work.