how to tell the difference between the 16v engines

[chrome233]

Basically im going looking at a 16v engine from a x reg vts
i need the 3 plug engine but as im buying just the bare engine with no anncilaries is thier any key indication as to wheter i have the single plug or 3 plug
do they have different engine codes for example
thanks

[Quick]

Look for the air pump bit on the head!