4.7 bored
Hall Of Fame
Joined: Mar 2009
Posts: 19,168
Likes: 23
From: South GA
As said before, boring out a cylinder will not change anything on the PCM. It will slightly lower the CR due to the cylinder being slightly larger but nothing noticeable IMO. But thats assuming you are using the same CC'ed pistons.
Rookie
Joined: Sep 2009
Posts: 60
Likes: 0
From: michigan
.020 bore will only give you about 3-4 more cubic inches on a 4.7L engine. This means only about 3-4 more horsepower, all things being the same. No PCM programming is not required for that small of change.