Nasty suprise when doing Intake manifold seals

[Regulus]

Will you do the valley pan gasket as well, while you are in there?
I hope you manage to clean out the old oil and sand.
As I am in a similar process, this can snowball pretty fast, as how much work you need to do.
The cylinder walls might be ok though. Removing the cylinder head will give you a clear view. Any sand that has fallen into the cylinder head might have stayed there, and not fallen deeper into the cylinders. At least that would be my guess.