What size piston and rings do I need for standard 205 pinto block arevthey same as other 2.0 blocks if so what sizes etc

If all you have got is a bare block don't assume it is std bore, it might well have been bored out.

 

Get a DTI gauge into the bores to get a measurement or take it to an engineering shop and get it measured accurately.

 

Are there any ridges on the tops of the bores ? if so I would be having it re-bored with pistons supplied to suit, new pistons in old bores isn't really a good marriage in my experience.

Ford had 3 standard size bores and several slight over bores you could have any of these in a standard engine

That said rings is rings it's just the gaps that need setting.

You could be lucky as I was recently and find that the new rings are within tolerance when measured or you may need to use a ring gap file wheel.

Rings are very hard and the gap faces must be filed parallel when fitted, not easy by hand

Haynes manual says 90.80mm, just doing mine at the moment,

Ivan