Just bought a BF ute from the Auction in Altona it was a stolen and recovered write off body is straight only the car has been thrashed.
There is a loud knocking noise when idling and on the written off vehicle report has it as cracked engine block we removed the gearbox and clutch to find that all the Flywheel Bolts were Loose. We removed the flywheel and cleaned up any marks from the crank and flywheel mounting face reinstalled it with the bell housing only and started the car the motor runs smooth no more knocking noises.
The mechanics that assessment of the engine fault was not accurate at all.

My question is it common for Flywheel bolts to come loose?

Also I need a new clutch kit and maybe a new Flywheel and Bolts.

What are you wanting to do with the ute?

Just a work ute like to my upgrade the clutch and flywheel to a non adjusting pressure plate.

You can run a turbo clutch (non SAC) in place of the SAC on the N/A. You WILL need the turbo flywheel however. The turbo setup is 0.5" bigger (and non SAC, obviously). I've used ARP bolts in mine. ARP-203-2802 are the bolts you need and can be had cheaper by using that part number rather than searching falcon. You will have 2 left over. You can get an Xtreme clutch kit with flywheel off eBay for a reasonable price. This is a H/D clutch too. That was cheapest kit I could get with flywheel included at the time.

I have done the same by using an aftermarket clutch kit that came with flywheel. The clutch is 10.5".