I am currently a student in grade 12th in a gifted high school in Vietnam, my GPA in Vietnam is 9.2/10 which is extremely good compared to my peers. However, when converted to US GPA mine is only 3.7/4.0 and I have seen many other students in the US have a 4.0/4.0 which could never happen in Vietnam.
So, they would still convert the GPA themselves when you send your application. Even though your GPA is a 3.7 when converted, they usually try to understand the education system and grading rubrics. To Determine if you're good enough colleges also look at your classes and course rigor you took.
Hope this helps!
This article I found should give you some information:
To keep this community safe and supportive:
In Vietnam, all highschool students are obligated to take up 13 classes and can't not take more. Do US admissions know about this?