Voltage Drop Help

[nokones]

I have two grounds from the battery; one to the chassis near where the battery is located in the radio module well behind the passenger seat of my C4 Corvette, and one directly to the all aluminum block. There is also a ground strap from the chassis to the block. I just looked up the conductivity of aluminum and it says aluminum is only 61% conductive of copper. I wonder if the aluminum block could be creating a grounding issue. I think I will run a ground cable from the chassis directly to the starter mounting bolts and see if that will help with the voltage drops. I guess that can't hurt.