Frickin' idiot!
I found out today there probably was nothing wrong with the head on my Maxx's 2.5. The glow plugs the idiot at our local HobbyTown sold me are obviously the wrong plugs for this engine. The thread size it right, but for some reason they won't seal. You can see fuel bubbling out around the plug when you use the starter. Now I have a spare 2.5 head, and I have the Nova Pro head installed. It is pretty, and is supposed to make the engine run a lot cooler.
For now, I'm running the the glow plugs I use in my Fantom which are not the correct length for the 2.5. The Fantom takes the short plugs. What plugs are you guys running in your 2.5's?