Thank you all for your input. I did further read the current series of THREADS here regarding Lithium batteries and am leaning toward these antigravity AND yes installing it below the floor boards. these appear to be 12v...Joel, could you physically measure LxWxH of your street rod batt please? ALSO someone posted a good LINK in WhteDarts Thread about new developing battery technology...in this they explain the worse cause of lithium battery degradation to be a rapid recharging rate...in the meantime before these 'tolerant' batteries are produced...HOW does a bracket racer with an alternator and pit charger replenish a battery at an acceptable rate?