Cranking psi is listed at 150 psi in the factory manual. Your compression numbers have a motor that will run, barely, however be down on power. I would pull the motor and plan on replacing. A 5.7 will bolt right in if you choose to upgrade
Start with the hose fitting on the drive that connects the hose to the transom shield which feeds the raw water pump
That fitting is part of the annual PM where you pull the drive and inspect things
I have an old 4.3 dizzy body with the gears ground off as my priming tool. if you pre-soak the push-rods in a skinny container of oil, it fills them up, less air to displace.
Block and heads are same GM parts. All others are specific Mercruiser or Volvo.
Make sure you are getting same generation of 4.3. there are 7 generations of 4.3s, and while you can cross generation lines in some cases, it's more work
Isolate and block the line from the raw water pump and the lines to the manifolds. Drain the block and heads of water, and pressurize to 15psi. It should hold pressure forever. If you loose pressure, listen for the hissing. That is your leak
on ignition systems..... NO.
all 12 volt batteries are about 12.7 volts fully charged and 12.0 volts discharged (below 12 volts just kills them)
as others mentioned.
Never use a cranking battery for a deep cycle application and never use a deep cycle battery for a cranking application.
welcome aboard
do you have paperwork (bill of sale and signed title/registration)? if not check with your local AHJ (Authority Having Jurisdiction.)
you may not be able to register it in your location without proper paperwork
