The truck has a 133" wb and we are trying to find the right parking brake spring. We also need to know if we need the cable extensions. Any help would be greatly appreciated!

 

Contact this guy, he just went thru quite a time locating e brake parts for his truck, but I think has all the #'s you need?

Ford Truck Enthusiasts Forums - View Profile: floyd rogers

Here maybe this will help?

E Brake- Pay attention to where the cable splits and goes from one to two cables. There are two different set ups. Here is what the Ford parts catalog calls for:
Cable, front, emergency brake.
Fits 78-79 F250 4WD reg cab, 133" WB cable length 108 1/2" long
D7TZ-2853-C
Wesley Obsolete Parts, Liberty, KY has 78 (606) 787-5293 Dennis Carpenter Obsolete, Concord, NC has 1 (704) 786-8139 Green Sales, Cincinnati, OH has 1, (800) 543-4959

D6TZ-2A635-C .. Right Rear Parking Brake Cable - 57 1/8" long / Obsolete
HAVEN FORD in Haven KS = 620-465-2252.
WESLEY OBSOLETE PARTS in Liberty KY = 606-787-5293.
GREEN SALES CO. in Cincinnati OH = 800-543-4959.

D6TZ-2A635-D .. Left Rear Parking Brake Cable - 65 3/4" long / Obsolete
HAVEN FORD or WESLEY OBSOLETE PARTS
GREEN SALES CO.

D6TZ-2853-B .. Front Parking Brake Cable - 89 5/16" long / Obsolete
GREEN SALES CO.
WESLEY OBSOLETE PARTS

Maybe the vendors above have the spring too?