I'm also an "airplane guy" whose kid has a T-Maxx. Setting the mixture seems to be more critical than cutting a hole in the body for cooling. You can easily get into trouble (too lean) even running WITHOUT the body. I'm also a hobby shop owner and have had many opportunities to set up/tune T-Maxx trucks for my customers. (I think cars more difficult to tune than airplanes!)

Want a foolproof way to set the mixture? Take it out to a wide open space so you can run it a while at full throttle (I use the local school parking lot). Start the engine and run it for a few laps to make sure it's up to operating temperature. RICHEN the mixture gradually until the truck WON'T shift into 2nd gear any more. Then lean slightly until it WILL shift into 2nd after a long straightaway. THIS IS A SAFELY RICH SETTING. It will be too rich for putting around the yard; lean slightly (usually no more than 1/4 turn). Same rule: lean mixture ONLY until it will shift near the end of the longest straightaway. You'll never get into trouble running around like this (unless your kids figure out what the needle valve does.....!)

Whenever someone has trouble setting one of these up I'll meet them at the local schoolyard and show them this technique. This seems to get them in the ballpark and I don't usually hear from them again. I'm sure that there are many other methods (probably better) that will work. I thought I'd share mine because it's easy and I've had a fair amount of success with it. I even bought an infared temperature gun to help guide me in setting the mixture. I still find myself reverting back to my original method because it's quicker and easier........