Bob, I would be a little concerned with too much heat and vibration on your batteries being attached to the engine that way. I build a little shelf over the engine and then soft mount the batteries using velcro straps and foam, never tying them down tight like that with zip ties. I had a battery break apart that way from the vibration and it kept shorting out intermittently on the igniton. Like to drove me nuts thinking I had an ignition or tuning issue. Beautiful Hellcat by the way. I have one of the old CMP birds unfinished yet.