brake hose question... C/20 to C/10

[Longhorn Man]

I am in the middle of converting my 3/4 ton burb to a 1/2 ton burb... The brake hoses on both 72 burb front ends were toast. One set was swollen like mad, the other set was dry rotted and cracked... looked like the dirt in a dried up pond.
Went to my NAPA guy who hardly ever got me the wrong part... at least, untill I got this truck. He gets the wrong part for the burb just about every time... gettin real old, real quick.
So he gets me $50 worth of hoses, and lo and behold... they don't fit. Too short.
Now, I went ahead and looked in my LMC catalog, and noticed the P/N for 71 and 72 hoses are NOT the same from 1/2 ton to 3/4 ton.
The Calipers are the same... the lines are the same, but the hoses are not.
Can anyone here tell me what gives?
Are 1/2 ton hoses longer?
Shorter?
Purple instead of black?
I briefly considered calling LMC, but I know my customer service call would be ignored in the order it's recieved.