I'm putting a big block in my 69 Dart that was originally a slant six. In order to save some money, instead of buying a new radiator I decided to use a 22" 340 radiator I have that I know has no issues cooling. But in doing so, I had to switch to a big block passenger side outlet water pump housing to match the bottom radiator connection. I now have to get radiator hoses for it. I'm not sure if 340 hoses will fit properly or not on a big block. Does anyone know of any big block cars that came from the factory with a 22" radiator and a passenger side outlet water pump?

looking in the white book I didn't see anything that looks like it.

Use some cardboard to make a template and go to the parts store and just ask to browse through their hoses

Coat hanger wire works well.

From the era , none . The outlet you have would have been used in the Late 70's C bodies but I believe they were all 26" at that point.

One thing you need to pay attention to is the pipe sizes of the 340 rad , I believe at least one of them is a little smaller than the 383/440 radiator, I've been looking at the ebay alum rads with the rounded top tanks to swap into my big block dart.

Yes, the top outlet is smaller in diameter than the bottom one.

None that I have heard of
Maybe some SB guys can post the outer diameter of the lower hose fitting on their water pump

i have used the universal chrome, flexible, "heat stove" material in the past to form a "hose", then go to seek one at the parts store.
although coat hanger or welding wire works as well, using the "heat stove" stuff allows a more complete visual aid to what the hose needs to be.
as to the size differences, most hoses today are so flexible, it "might" be able to be pushed onto a slightly larger radiator hose nipple.
however, you might get lucky at the parts store and find one of the correct size.
there are also "hose reducers" available if you find a hose that is larger than the radiator nipple.
don't forget to wind up a wire to fit inside the lower hose if it doesn't come with one. [most do not] this will prevent it from collapsing if the pump sucks really hard at a certain rpm.
1/16" or so stainless wire can be had from most good hardware stores, and can be wrapped around a broom handle or piece of pipe slightly smaller than the id of the hose.

cant see why a 60880 and a 60878 wouldn't work.

what brand are those numbers from ? gates maybe ?

Continental, but there are probably other that use them.