That same paragraph is in the '99-'06 (except '06 Dynaglide) instruction sheet...

"All Andrews Products 21HG, 26HG, 31HG, 37HG and
50HG Twin 88 cams are made with stock size lobe
base circles so stock pushrods will be the correct
length. If you are going to use the original pushrods,
removing the fuel tank(s) and rocker boxes will be
necessary. Mark the pushrods so they can be replaced
in their original locations. (Not all stock pushrods are
the same length). 54HG, 55HG, 60HG and other high
lift cams will require adjustable pushrods."

So, yer on the right track. The email you sent should verify...

 

Adjustable rods would be the route to go here.