Hey new to the Forum, I recently bought my Buddy's '02 150 with a locked up 4.6 for $800.

I already picked up a used engine out of an '03 from LKQ. I'm pretty familiar with Modular engines and I remember reading that there was an update to the heads in '03 where they got more threads in the spark plug holes. I tried searching around for the info but I couldn't find it, anyone know the production date that Ford started using the updated head?

 

Think its after Jul 03 build dates.

 

the heads went into production November 12/02. I was looking for the updated heads all over when i was replacing my motor. I found motors assembled as late as April 1st 2003 and they did not have the updated heads. This was on windsor motors anyway.