https://www.svtperformance.com/threads/saving-weight-antigravity-battery-morris-engineering.1133785/
I did this battery and mount almost 2 years ago and it is still working like a charm.
-Satch
I had this battery on my old Boss 302. I only drove the car once a week, once every 2 weeks sometimes. Car always turned over quick and it seemed like the battery never lost juice! Even brand new, a Motorcraft battery didn't do this. If doing it again, I might go with the larger style like @BAS has just so I could keep the factory tray.