<p>I am looking to set full trust for a single web part, is this possible?  manifest.xml maybe?</p>

Have you tried registering the assembly in the GAC? This is the preferred approach to giving any assembly full trust on your machine:
```
```
gacutil.exe \i C:\Path\To\Dll.dll
```
```
Hope that helps. Let me know if I misunderstood your question.