Aftermarket Six Pack Questions?

My best suggestion would be to check out a thread on fbbo, called "tripower carbs on 440 six barrel". Sonny started the thread to find out if he could use corvette tripower carbs to put together a sixpack setup for his 440. Eight pages of info about how it was done, with new carbs, manifold and aircleaners, on the cheap (relatively!). If you dont need them to be original, and "correct", that might work for you. He says his setup saved at least a thousand bucks.
And for what it is worth, the 440 carbs are so similar to the small block carbs, i cant tell the difference except by looking at the numbers, htey will work just fine on a small block.