Trunk Mount Batt. Opinions needed

Did it ever crank over Ok? If so could be weak battery. Not sure what 1ot. is I assume its 1 gauge. I think you may need to go with a larger size (USE WELDING CABLE) for starter and chassis not the regular automotive cable, double check connections use dielectric grease. Unsure it the frame rails would be as good a connection point as the body itself. Maybe a jumper from the body to chassis. I would not use the disconnect another resistance point not needed, make sure wiring to run is fused at the battery.