I've tried ielts 2 times, but stuck in the writing. then i changed to pte, first time i got all 7 already, then on my 4th time, i got all 8.
u can try to go to enflares.com, it is very useful resources.
i also join some pte wechat group, they h. online classes, u can see if u wanna join
I think you can get writing 8 in PTE....
PTE is in a different format and assessment method.... based on your IELTS score, I personally think that you should have no problem in PTE all 8