This link gives the VW version. In all honesty you do need an air-flow comparison to do the job properly, though the balance pipes will compensate if the adjustment isn't as close as desirable.
You also need to make sure the carbs are clean in all their passages, the joints have good gaskets, the manifolds are tight to the heads and the balance pipe rubber connectors are in a good state and fitted effectively.
http://www.thesamba.com/vw/archives/man ... /index.php