DIY MH Questions

[GrandeGixxer]

Ok, I got a couple of questions before I fire these tomorrow. The box I have to house the ballasts is steel, powder coated and has a gasket seal around the door. It is pretty much weather tight except the few holes that I have drilled in it. Am I going to have any overheating problems.

Also, I have the ballasts mounted through the factory holes in the ballasts. The part of the ballast that protrudes from the sides is against the bottom of the box. Is it bad for this to be touching? I could pretty easily make some little wooden standoffs for it, is this going to be needed? I don't want to cause a short.