This guy has a bunch of posts about this at GMforum.com, I had pointed him to NEPontiac.org to look up the pin swap that you mention above. However...he had issues.

Quote Originally Posted by xtremerevolution View Post
I need to know if a 99 year Pressure control solenoid will physically fit into a 03 4T65E transmission.

I think I figured out my transmission's problems. I'm using a 99 PCM and an 03 4T65E and people suspect that the reason my transmission doesn't shift properly is because the 99 PCM can't communicate properly with the 03 PCS. I have heard that they are electrically different. It will slip into gear unless I raise PCS pressure, but the shifting is erratic at times and the car goes into limp mode within 15 minutes of driving with no other explanation.

So, will that PCS physically fit into the transmission?
More on it with the link to NEP
Need transmission tuning help! - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat

Pay attention to the dates of the posts as it can become confusing and then ensure you see page 8 where he talked to Dave abotu the pcs being different
03 4T65E slipping in 1st - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat

this is all why I suggested swapping the valve body/channel plate in the pm.