Cortina MK2 - When was changeover to Crossflow?

[allanv6gt]

Hi all, wanted to ask a Cortina-newbie question.

When did Cortina's change over to the crossflow motor?
(I seem to recall the early MK2's were 1500 pre-corssflow)

Was there ever a crossflow 1500cc motor, or only 1600cc?
What did the GTs come with engine-wise, across which years ?

Thanks in advance