GP3300's no matter how much shrink wrap you put on them fit, within reason. If you are faced with the delima of the newer cells not fitting, you can always raise the battery brace mounts, place an o-ring between the chassis and the mount, and the new cells should fit, if this doesn't work, space it some more. I have never had problems with double shrinkwrapped cells fitting in any of my G+ chassis's. If anyone is having problems with the car or are looking for a set-up feel free to contact me about it. Also, if anyone needs a list of good mods to the car, feel free to contact me on that too.