I'm new to this forum. I was hoping for some help with my truck. I need a brake proportioning valve for a 77 dodge power wagon, W200 3/4 ton, 400ci 4X4. I can't find one anywhere online or in parts stores. Does anyone know where I can get one or if I can swap one from another year or model. I need to get this truck back on the road. Thanks for your help.  

I believe you can interchange parts between 72 and like 79 if I'm correct.  I'm not 100% sure.  YOu might look in wrecking yards to see if they have one.  

try www.jcwhitney.com. they got tons of parts for just about everything out there.