I cannot remember everything. There is no purpose ground connection on the starter . It is grounded through the starter casing to the engine block. So attach the ground to somewhere on the engine. Or use a starter mounting bolt to the housing for the ground if practical. You want the positive cable to the upper side large terminal on the starter in most cases. Not on the large terminal that has a strap or wire entering the starter motor itself. That terminal is just to process the voltage to the motor once the internal switch in the solinoid is activated.

The solinoid is then energised by touching a screwdriver between the small terminal and the large powered terminal once this is done. The solinoid closes the motor power switch and moves the starter drive forward into the ring gear as well.. In effect you have completed the circuit the key switch normally does to activate the starter.

If you put the positive cable on the top large terminal and the negative on the lower large terminal. Then activate the system you may no longer have a good solinoid. It would probably burn out the switch contacts in my opinion. Or weld the switch contacts together in the solinoid. Anyways forget putting the negative cable on either terminal. Take it to the block.

If you use the wrong large terminal for the positive connection the starter motor will just spin continiously without the starter gear engaged with the ring gear.

Now if the compression tests work well I would remove the lower oil pan cover and plastigauge the first rod bearing. This is a simple and cheap method of checking the clearance. Can be done after the purchase if the engine checks out well compression wise.

If the 616 engine is run for a long time with low injection pump base pressure. For example never changing the secondary fuel filter until it obstructs. The number one cylinder bears a heavier loading than the other cylinders so excess wear can be present on the bearing. This in my unproven opinion is the reason for the larger incidence of the number one rod failures on the 616 engine. So if that bearing is worn more than it should be. Change it before installing the motor.

There is also another great contributor to this issue on the 616 engines as well. This can be left for another time after the engine is installed to check.

Other than this these engines are pretty well bulletproof if the oil was changed as it should be and total accumulated miles are not too great. Make sure you have valve lash clearances on any cylinder that checks low before condeming the engine..

Many owners where not even aware the valve lash is not automatically dealt with. As it is in cars with hydralic lifters. Valve lash was recommended to be at least manually checked every fifteen thousand miles. So some of these engines developed basically no lash with no maintenance and the valves do not close well enough to get a proper compression reading.