I have a SBC in my 67, has run and started fine for several years. Battery is grounded to the bolt that secures the alternator to the block, have a thin guage strap from the firewall to the distributor hold down bolt on the Edelbrock Performer. Again have had no starting problems with this setup. A few days ago I put a ground cable from the engine(the hole used to mount 55-57 SBC mounts) to the front crossmember. Now instead of starting instantaneoulsy (sp) it takes a few turns before it fires. Weird. Can one over ground a beast?