Hello. I had a ground on the alternator bracket but moved it. Where is a good place to run a ground on the block to frame?

 

My grandpa was a real stickler when it came to grounds, and all things electrical. He would always preach about running a good ground from the body to frame, frame to block, and body to block. I've read it several other places over the years as well. He was so dead set on this that he'd use old welding leads for his grounding cables. It definitely seemed to work well on his 49 mercury w/ big block swap. that thing ran so smooth. Something to consider if you haven't already.


Maybe consider using one of the four threaded bosses on the driver's side next to the milled surface for the mechanical fuel pump? keeping it away from the heat on the passenger side...as you're running headers.

 

On mine, I have several grounds. One goes directly from the negative battery terminal to the fender right next to it. Another from the negative battery down to the frame. Then from the frame to the starter.

On the driver's side, I have a metal ground strap from the block to the firewall. The block is held on with a bold and the firewall with a sheet metal screw.

Can't have too many grounds.

 

For my son's 1984 and my 1986 F150 with 4.9L engine, the original ground cable ran from the negative battery post to one of the starter mounting bolts. Midway of the cable length, was a metal tab which bolted to the frame.

This is aftermarket, but it looked something like this:

 

The engine starter is the biggest current draw by far, so running direct from the battery negative to a bolt on the starter isn't a bad plan. The OEM routing isn't necessarily a good plan to follow because they were all about saving money on cable/copper. Over time brackets and frame and connections become corroded, they might have worked OK when new but after a few years of exposure to road salt and pollution the corrosion causes bigtime voltage drops. This slows starting and interferes with charging. The starter will draw the current it needs, wherever it can, if the ground or return path is bad, that's when you hear of things like red hot accelerator linkages, brake lines etc. A couple hundred amps of current can do some damage when it's routed through something that isn't designed for it. Good grounding is important.

 

I could not find a NOS replacement at either time [1st replaced the one on the 1984 and later, the 1986]. On the 1984, went all the way to the starter mounting bolt and then piggy-backed a shorter cable from same bolt to the original location on the frame.

On the 1986, ran a cable to the unused upper bolt [previously air pump location] of the alternator bracket and piggy-backed one from the same bolt to the original frame location. Both configurations work.

 

This is what I did on mine. I like it.