Unless the spec just changed the meters on all the latest engines is a 70mm unit.
If you're after something with really good flow capacity and don't want to stuff around look for the Pro-M 77 meter through a yank supplier. It'll cost you around US $400 but its a well designed unit. Unlike our 70mm meters this Pro-M model has the sampling tube built into the wall of the meter so there is considerably more airflow.
If you want to see ads pick up a copy of 5.0 Mustang or Muscle Mustangs & Fast Fords from a newsagent (it may take some looking).
The manufacturer has a good web site here: