2L pinto difference. early and late model

[GTMRK2]

gday guys I have a 2l pinto with a auto trans out of a te Cortina, im just wondering if they are the exact same as the early mk2 escort 2l's ? ive heard the later te motors had thinner walls in the block not sure if true or not, is that true and any other difference in the block and head ? any info would be great I want to build a hot 2l wondering if I should just buy a escort 2l instead, cheers