No, it doesn't necessarily have to go back on alternator bracket...but has to be somewhere on the engine block. Whatever you do...do not...l repeat...do not...use an exhaust manifold bolt. Had a friend do this...lol. Remember, the exhaust gets pretty darn hot, which in turn melts the solder inside the cable end. Friend was showing me his engine swap and l looked down and saw bubbling solder, reached down and pulled cable out and car died. He just looked at me like...??? I'm like...l think you need to relocate this connection...lol.

 

I don’t think I would attempt to pull a manifold bolt. There are additional mounting threads on that bottom corner of the block. I think I will re-orientate the terminal cable to this.

The bolt which broke - doesn’t appear corroded - so as I remedy this. I’m fearful this isn’t the culprit..

 

There are only a few components to the primary starting system. A fresh/charged battery, clean/tight cable connections at battery/starter/ground on block, cables of good condition, supply voltage from ignition switch and a good starter. If you have all of these conditions...it should crank over easily. Only other issue could be something mechanically (alternator or pulley frozen up, not allowing engine to turn over) or fluid in cylinders (anti-freeze in cylinders). Usually, if anti-freeze is entering cylinders...it will initially turn over slowly (or not at all, if hydro-locked)...but will eventually start to crank over normal as fluid is cleared from cylinders.

 

I would take the wiring out of the situation. Take a pair of jumper cables. Run battery positive directly to the big starter connection, and run the negative to the starter body if you can. If not then just on a clean spot on the engine block or bellhousing around that area. Then try to crank it over and see if that makes a difference. If it does not, you have a problem in the starter or the starter solenoid, or your battery is in fact bad.

If it does help, then undo the ground and try again. I expect your ground is not the issue, but I have nothing to base that on but a guy feeling. If your issue does return them you have a grounding problem. At this point I would recommend running a ground from your negative battery cable directly to one of the bolts holding the starter in the block. I'd say around 6 gauge.

If it is still starting correctly then undo the positive connection and try again. If your issue returns then you have an issue with your positive line and will need to run a new one. Again, use at least 6 gauge wire.

 

Well, there is an additional mounting location just next to the battery block ground; I cleaned the threads with a tap & picked up a new M8 bolt - charged the battery and it fired up strong.

It’s hard to believe that the little corrosion about the block ground would cause this, but the bolt snapped off - I wonder if the intrusion of corrosion down the threads would have made for a poor ground?

In either case I will keep an eye on it & I appreciate & value the support here. Thank you