you should remove the PMS system, and drop the car off at a reputable mustang shop.. and have them tune your car with a 4 bank SCT chip

 

The cam is at 8 degrees of what? 8 degree retarded? 8 degree advanced? Is thea stock cam or aftermarket?

Your posts are very vague, missing alot of key info, andbeing such make it very difficult to give you quality help.

Are you certain that the PMS is set to 38° at WOT and isn't retarding based on boost or RPM? I'm certain that you cannot have 38 degrees of total timing at WOT without breaking something.

I have had two 94+ 5.0's with S-trim blowers and both used the PMS to some degree of success (10.0's @ 138mph with a similiar combo as yours). Though I do think that there are better solutions that the older PMS units out now it is possible to run a safe and fast program off the PMS if done properly. I'd suggest finding a good tuner in your area and having them get the car dialed in for you as it seems like you don't know enough about it right now to take care of it on your own.