I am going to use a dry cell battery in mine, so I don't have to use a sealed / ventilated battery box. I think with the ground cable I will ground the chassis in the back, and run a lighter guage wire to the block, then block to chassis. The positive wire I'll run a larger guage between the starter and soleniod.

For me, 2 reasons.
1) I have a big block, so lighten the front end, mor weight on the rear: better traction, handling etc.
2) It allows me to clean up the engine compartment.

 

Except for the safety thing when racing, I still am not convinced that moving the battery to the trunk makes any difference in the performance of thecar. A battery cut-off can be accomplished a lot easier and less expensive than moving the battery to the trunk. If you want more power, add some goodies to the engine. If you want more weight in the trunk, add a sand bag to the trunk, add traction bars, racing slicks and posi traction. I guess what I am saying, is to do something that will actually make a difference in the performance of the car.

 

well the only reason i put batteries in the trunk is becasue they are ugly and i feel they look like crap in a good clean engine compartment. i dont really think that there is any real advantage for putting them in the trunk.

 

Its sorta like rice burners putting on fart cans...all for looks LOL

 

In a classic mustang it give you extra room in the engine compartment especially when you are doing a conversion to an V8 in a 66. And like you said Soaring performance wise it probably does not make a bit of difference, but on the other hand every bit of weight counts.