is the transfer tube on the A body Kelsey 4 piston calipers
a standard 6 or 7 inch brake line and fittings.
i'm rebuilding my calipers and would like to replace them.

Where are you getting your rebuild parts? I've got some that need rebuilding too. I see Advance has seal kits for $9.99 but I assume you need 8 kits for both calipers?

I was going to soak my transfer tubes in EvapoRust and see how they come out. I could have them zinc plated with the rest of the hardware when that time comes.

One kit does one caliper, BUT you need to make sure it has the correct dust shields. There were two kinds, early and late. The early seals go around a lip on the caliper while the later seals go into a groove above the o-ring groove. Since these are the same kits as 65-67 Mustangs (and, I suspect, they only use the early seal) some kits only have the early seals.

You can buy New hard lines on the calipers from Fine Lines.

The picture on Advances website only shows one seal and one dust boot...that's why I assumed you needed 8 kits for both calipers.

..Mine are in good shape.The only difficult part was removing the pistons which are now all out and being stainless polished up like new.
.i have taken the transfer tubes off now and will check
these at my local auto parts store,or if necessary order from 'fine lines'
..tx guys.

..just checked and the transfer lines are standard brake lines and fittings.

here's the lines you need the right stuff brakes
http://www.getdiscbrakes.com/partfinder/product/list/?year=1970&make=Chrysler,%20Dodge,%20Plymouth&model=A%20Body%20-%20Barracuda,%20Dart,%20Duster,%20Valiant&category=Brake-Lines&cat=1254