8 singles on a 1973 340

agreed, MAJOR hassle. i had enough trouble setting up two dueces on a chevy inline 6, although once i figured it out it ran GREAT. 8 carbs should only be used on nostalgia drag cars and wild show cars that don't need to be driven. and if you do manage to find a manifold, its probably going to be 8x2, not 8x1.
If your handy with the TIG welder, you might be able to fab some kind of sheet metal manifold, but again, is it going to be worth all the time and hassle. IMO, not. but it would certainly blow peoples minds at the cruise nights.
-Tim