Engine rebuild

[Gaelicguy]

Good day all,
I’m starting to re assemble my 2.0 engine.
All the parts were vapour blasted and the machining and balancing was done by David Murray in the UK.
I’ve searched these items and found nothing so far.
1. I’ve read somewhere that it is a good idea to seal the inside of the magnesium sump with epoxy. If so has anybody got a recommended product ( there are lots of choices these days)
2. I would like to reflush the coolant galleries as the core plugs all show accumulated dried grunge. Any recommendations?
3. Replacement gallery plugs, aluminium or brass?

[Gaelicguy]

Another rebuild question,
I have read that the cam chain drives bearings ( the drive from the crankshaft) would benefit from self alighting bearings.
Is that all 4 or just 2 of the 4?
I already have 2 new self aligning bearings.
Thanks
Michael