Darn those trunk batteries, sem to be jsut a pain
Put the remote solenoid as close to the starter as possible. I have mine on the passenger fenderwell for easy "bumpin' over" access, but you can hide it below the heater core stuff if your a tidy person.
You can even use the above HOT post on teh solenoid to deliver power over to the fuse box and other stuff with a nice 8 or 10 gauge wire along the fire wall.
As for the ground. the battery will go to the rear frame some where. be sure to jumper a thick 2 gauge battery wire between the frame rail on the pasenger side up to the block somewhere. MAybe a header bolt on the rear, or a head bolt if it's convienent. Heck, I'd even put it between one of the start bolts and the starter nose! If you can keep it away from heat. Then put another "braided" strap from the frame (up a ways) to the from of the block, maybe an accesory item tie down.
AS for the pump. same one I run. be sure it's not directly to the trunk or frame. put some rubber grommets or bushings in there. She resonates like crazy!
Come straight off of the battery out back with a 10 gauge wire, to a 30 Amp (fog light type) relay. keep it close to the battery. then run the wire out somewhere to the pump. I grounded my pump just to it's mounting point from the trunk wall. but you can run it back over to the frame ifyou so desire. Now you'll just have to run a "control signal" from the fuse box that is switched. Most likely the "ignition" terminal. Run it back to the relay to energize the coil. Nothing but 16-18 guage stuff is fine. Might better put in a switch for this wire to cut off the power when you don't want it on.
good luck with it all, and remeber to make all connections touch metal, even if you have to wire brush some paint away. A welded bolt on the back frame near the battery for ground is a smart choice.
71' 3880# with me. Big Block 402, Merlin oval heads, 10.2:1CR, TH400, 3.73 posi,
BEST 1/8th: 8.252 @ 84.56mph (1.855 sixty foot)
Last years previous best 1/4: 13.1sec @ 105 MPH (2.10 sixty foot) to be corrected soon.
Picture of me roasting the tires and other guy stuff
Video of me staging (smoke of course)