one fuel line or two

on the ltd1000 my carbs have one fuel inlet, but the petcock has two comming off of it, seems like I remember the 900 as having 2 on it.
does it make any differance or not?

Are you sure that isn't a vacuum connection for the vacuum actuated fuel?

no, it has a manuel petcock, and besides gas flows out of both barbs real well

I'm surprised that the '77 KZ1000 doesn't have the same plumbing as the '76 KZ900. But you've got both models, so you ought to know. Seems like, if your tank petcock has two ports, then it should supply two hoses, and there should be two inlet ports on your carb rack. Must be a pretty big fuel line going into that single feed port on your carbs.
Aftermarket carbs?
My 900 has two ports on the tank valve. One fuel line goes between 1 & 2 carbs, and the other goes between the 3 & 4 carbs.

the carbs on the 900 are not there, a bud borrowed them and I never got them back, nice guy, that was what got me to thinking.
the fuel line is 1/4 ID, kind of has me wondering about the fuel delivery if it is wanting to lean out on top end

Your carbs are probably not the original ones. The 900s had twin fuel inlets, and the older KZ1000 series did too except for the 1979-80 KZ1000MK2 and ST which used a single fuel line. Possibly the 1980 KZ1000LTD used single too, but 1979 and earlier should be dual. You can run a single line just fine if you "T" your dual fuel outlets into a single line.

78 Z1R had only one fuel inlet as well...

As far as 1/4" ID fuel line, it is fine... look at your fuel pipes and you will see that they are far smaller than 1/4" and they would likely be more a restriction than the fuel line.

Have a look at your petcock. In the late 70s, Kaw switched to a vacuum petock with two spigots. One for gas and one for the vacuum line. The spigots will be a bit different size since the vacuum line is much smaller ID... (vacuum spigot will be smaller than gas spigot). If your petcock says ON RES PRI, this is what you have. If it says ON RES OFF, disregard last paragraph.