Hi,
If that white smoke doesn't stop, it does look like a head gasket. You have a lot of miles on this engine. Was it running good prior to this happening? I don't want to see you put time and money into it if the engine is worn.
I attached the directions for replacing the head gasket below. The first set of directions will cover the left side and the second is the right. Many of the steps in the directions are repeated, but there are differences. Also, if this engine has 300K miles, I recommend replacing the timing chain and tensioners. Additionally, you will need to purchase a gasket kit because reaching the head gaskets requires the intakes, valve covers, and so on to be removed. Note: Once the heads are reinstalled, you will need to make sure engine timing is correct.
This is a big job, so don't be overwhelmed by the directions.
Let me know if this helps or if you have other questions.
Take care,
Joe
See pics below.
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Friday, August 19th, 2022 AT 10:06 PM