help! chargeing problem since mad bypass!!

You can use wire to the block. The thing is, the block is sometimes poorly grounded to the body, which is yet another aspect of this problem

Think in your mind the "path" of the ground.........and each potential "bad connection along the way

Battery neg post / cable clamp

Corroded inside the cable at that point.

Same down at the block

Many factory cars had a minimal ground PIGTAIL from the NEG battery clamp to the fender sheet metal, so THAT is a point of trouble.

Many had, or "had added" one or two no 12 or so wires / straps from the block to the firewall.

On V8s you have the same holes in the rear end of the driver side head as you do in the front on the pass. side. I like to use a a short "ring to ring" or starter cable. Bolt to the rear of the head, and bolt either to a bolt through the firewall, or to one of the master cylinder studs.