The Classic Industries number are as follows in these links...
Long Bed 67 - 72
https://www.classicindustries.com/pr...s/tin6808.html
Short Bed 67 - 72
https://www.classicindustries.com/pr...s/tin6801.html
There is no difference in the front to rear pipe for either coil or leaf rears, as the pipe exits the chassis at same place.
"Special K is a hoot aint he !!!!