You might try calling...
S&W Diesel in Wilmington, CA...(310) 835-3155
TAD Diesel in Hayes, VA...(804) 642-9296
Mr. Cool...(866) 726-2665 or www.mrcool.us
In can cough up some more names...but those are folks ive used a lot for my Perkins and have had good luck with.
If you have the part number from the current one, or your engine serial number (or just build number prefix) handy, it may save some hassle.