Longhorn pump to carb fuel line

[davepl]

I have a '70 402 Sierra Grande Customer Camper, which is the GMC version of the longhorn. In trying to order the right fuel lines, I confronted a problem:

In the catalogs I can order either:

a) 1970 402, short fuel pump
b) 1970 Longhorn

They're two different lines. First off I can't imagine why a longhorn would have a different carb to pump line (since most of the difference is in the rear frame). But the "1970 Longhorn" doesn't differentiate small block to big block, which is also weird.

I'm guessing either I need (a) above or a 70 Longhorn 402 is a -third- different type that's just not listed.

Any Longhorn afficianados know the answer?

Thanks!
Dave