You are making a BIG mistake by using stacks on a street car. It doesn't take much time for an engine to pull in enough grit to trash itself with unfiltered air and besides, stacks are of nearly no improvement in performance under regular circumstances.
The reality is that the part of tuning that involves velocity stacks is extremely precise and can only be performed after everything else is brought into strict compliance with a very detailed construction process, read "specialized racing engine". From that point on the best way to spec stacks is on a dynamometer or less accurately on a test track.
The best thing that you can do for normal street use is to use the base plates from the stock air filter canisters and install DEEP style filters over them. The standard depth filters, K&N or stock style paper ones, allow for a relatively calm pool of air to be presented to the carb throats and the radius of the stock base plates is near on to being perfect for air turbulence and transition into the carbs themselves. Hap Waldrup and I and several others have worked up varying approaches to using these base plates, some being more elegant than others. I am not sure if Hap has posted his work on this board. If he has though you should be able to find it with a Search. Otherwise let me know and I'll shoot you some information.
K&N supplies naked filters and ones with chrome cover plates. They both allow more flow than stock paper ones and in doing so sometimes require changes in mix or even changes in needle profiles. Stock paper filters allow plenty of flow for all but the most demanding performance AND they are cheap. If you want to ditch the canister cans you can use the allow base plates and either make a set of covers or buy a pair from Rusty Koester at
brokenheartstudio@gmail.com or brokenheartstudio.googlepages.com/hom. I use Rusty's caps as I found that making a good looking set out of aluminum is WAY more time consuming than it looks. LOL
Jack