As long as the carbs orignally came off the same type of engine,50's Powerglide 235 for example, they should be close enough in specification.
I had dual Rochesters on my 261,they didn't leak from the bowl gasket like most, but on hard acceleration, fuel dripped down the accelerator shafts onto the manifold.But in my case, the Rochesters carburetored quite nicely on a heated manifold.The stock main jets in mine were fine, I believe the jets were #56's
