As GD says, yes. I reckon it is the only way to do this job for best results. And yes on reuse timing belt housings to preserve cat and possum tails from skipping the belts. I would fear getting a flock of massive hoppers stuck between belt and cogs when least need a belt skip
Yes you can install the cam seals in the housing first. DO NOT use the bolts to attempt to draw the housing down. You will break the housing. VERY gently tap and twist to get the housing seated against the o-ring (replace the o-ring obviously), and only tighten the bolts once it's fully seated.
GD
So the engine is out and I've found the culprit.
One of the freeze plugs had popped out in the head.
Just waiting for my water pump to arrive and I can do a pressure test on the cooling system to see if I need to delve deeper.
Dropped the sump off and apart from a load of milky oil laying in the bottom it looks like the crank is in good condition.
Also managed to free off the completely stuck distributor, given a clean up and back in.
Good weekend so far.
We tried every conceivable resolution. The customer certainly wasn't excited about pulling the tank. Ultimately we had to pull the tank after the car came back for about the third time unable to fill the tank and with codes, etc.
GD