Which front brake hoses to use

[CARR33]

I am doing a complete suspension / brake system rebuild. Some p.o. Changed the front crossmember in my 67 1/2 ton. I got a rear disc brake kit, and would like to replace the front calipers and hoses also. The problem is that i dont know what year stuff is on the truck, and the parts books list hoses for 71-72, then 73-78. I dont know what the difference is. Mine have a 1" square block at the caliper that is beveled on the opposite side of the rubber hose. The banjo bolt goes thru a hole in the center of the block. The hose is approx. 12" from the banjo bolt to the opposite end. The mounting tab on the crossmember to attach the hose to the hardline is on the front, but there is a tab on the rear also, but it isnt drilled. Any suggestions?

[19stepSide72]

pics might help?