Change transmission, should I change the engine too?

Hello,

Generally speaking, unless there are specific issues with the engine that is not repairable then you want to replace the engine.
However, you don't have to replace the engine simply because of the mileage of that you are changing the transmission.

I have attached the transmission replacement procedure below for your reference.

Please let me know if you are experiencing any particular issues or if you have any concerns.
Thank you.

https://www.2carpros.com/articles/how-to-remove-an-automatic-transmission-rwd