In an effort to quiet down the carbs, I picked up a factory metal air filter box. That was a big improvement in intake volume from the individual K&N's , but the front cover for the air filter does not have a snorkel at all. It looks as though it was cut down flush with the cover.

What kind of volume decrease would I see with a proper snorkel fitted to the intake box?

And for what it's worth, the motor is a 2.7 built to RS specs with S cams, not sure if the snorkel would cause an air restriction to the airbox.. The diameter of the snorkel inlet and air filter cover are different, so I'm assuming there would be a little bit of restriction.

Looking at goign from this:


To something like this:

Snorkel should be fine, seeing as the factory MFI cars had them:

It's purely a sound preference, as I've seen them running with the warm-up setup shown above, with a long snorkel like you show on carb'd cars, short snorkels and no-snorkel (cage picture shown).

Don't be swayed by a picture of one of Magnus' cars

BTW I'm going to run the alumn bellmouth I got from Britain: