OK, so I made a plywood box to check space, and it looks like moving the battery to the trunk is the only way to make this work and not look like caca - too many things were positioned based on that little battery volume. A question:
Charlie mentioned running the ground cable to the frame, then a short frame to block cable up front. In the trunk I have a very convenient body mounting bolt that threads into a nut welded into the frame, pinching the fiberglass body between the body brace plate & the frame (frame nut, anti-squeek body welting, fiberglass body, internal bracing plate, washer & bolt). Seems to me that putting the battery ground atop the internal brace plate, then using a similar bolt up front for the block ground will work fine. I have a 3/8" bolt into a nut welded into the frame on both ends carrying the current. Battery positive will penetrate the trunk floor and run direct from the (+) terminal to the starter, with a jumper to the bulkhead to get (+) power into the cabin. Sound OK to you guys?