Can anyone direct me to a location that I may find some information about if 8 digit routing numbers are appropriate and where I can find a list if what numbers are only 8 digits?

Some of the following is out of date, but not the repeated reference to 9 digit routing numbers. A bank's chances of having an 8 digit routing number are equal to yours of having a 8 digit SSN:

Regulation CC

Appendix A to Part 229--Routing Number Guide to Next-Day Availability Checks and Local Checks

A. Each bank is assigned a routing number by an agent for the American Bankers Association. The routing number takes two forms: a fractional form and a nine–digit form. A paying bank generally is identified on the face of a check by its routing number in both the fractional form (which generally appears in the upper right–hand corner of the check) and the nine–digit form (which is printed in magnetic ink along the bottom of the check). Where a check is payable by one bank but payable through another bank, the routing number appearing on the check is that of the payable–through bank, not the payor bank.

B. The first four digits of the nine–digit routing number (and the denominator of the fractional routing number) form the ‘‘Federal Reserve routing symbol,’’ and the first two digits of the routing number identify the Federal Reserve District in which the bank is located. Thus, 01 will be the first two digits of the routing number of a bank in the First Federal Reserve District (Boston), and 12 will be the first two digits of the routing number of a bank in the Twelfth District (San Francisco). Adding 2 to the first digit denotes a thrift institution. Thus, 21 identifies a thrift in the First District, and 32 denotes a thrift in the Twelfth District.

a lot of our software applications drop the lead zero. is there a possibility the routing # you are looking for starts with a zero?

Canadian RT's are 8 digits long. Maybe it's a Canadian check.

Ancient history: Back in the day, shortly after MICR encoding of routing numbers was mandated on checks, routing numbers were only 8 digits long here in the U.S. For example, the routing number of my first bank employer was 0113-0655 and the routing number of the bank I ultimately retired from was 0113-0574. And that's the way those numbers were encoded on checks, with a MICR dash symbol in the middle.

Problem was, mis-sorts occurred. I vividly remember my father being charged by his bank (Hyannis Trust 0113-0574) for a check written on the same account number at Attleboro Trust Company, another bank that used the same account number scheme but had a routing number off by one digit from Hyannis Trust's).

To prevent mis-sorts, a check digit was added to routing numbers, and it was calculated and checked on the fly as checks were read in the reader-sorters of the day, so that a misread of any one digit would cause the check to reject. Because there were already nine spaces assigned to the MICR routing number field, the hyphen was dropped to accommodate the check digit.

This might get you going in the right direction...

http://en.wikipedia.org/wiki/Routing_transit_number