grounding wires: flat specialty or round battery cable?

[luvbowties]

I'm thinking of using solder lugs to convert the ends of buggered-up-ended battery cables--from 2-ga. to 6-ga.--to 'eye-loop' type and then bolt them on to ground such as block-to-frame, block-to-body, block-to-cab, frame-to-bed, etc. Are there any disadvantages to using these round wires vs. flat stranded wiring made specifically for grounding?
I realize the cost, with solder lugs, would be greater; but since I have no other use for these deteriorated-end cables, thought I'd use 'em for grounding, if there are no drawbacks.
Thanks for ideas and caveats.
Sam