I have the same problem w/my mbx-5 and my batts. BrianG recommended a 10mm spacer on the body posts to help w/this prob. I have tall batts. and I am not to sure if this will work. For now I am living with a crooked body. In this pic. it is hard to tell, but the batts are quite tall....they are almost to the top of the esc.
1. MBX-6 T8 1900KV, RX8 ON 4S
2. MBX-5T 1520, MMM ON 5S
3. MBX-5 ONROAD CONVERSION 1515, MMM ON 5S
4. MRX-3 ON ROAD CONVERSION 1512, MMM ON 6S
5. TEN T 2650 T8, MMP ON 3S