is it possible to install a pinephone pro mainboard in a pinephone

[fxc]

i would like to know if it is possible to install a pinephone pro mainboard in a pinephone for an upgrade of the cpu, ram and storage

You will find your answer in Pinephone Pro's webpage here.

Specifically

I am a PinePhone owner – will I be able to upgrade it by installing a PinePhone Pro mainboard?

Probably not. While the PinePhone Pro’s mainboard will fit the PinePhone, the chassis, IPS display panel, cameras, the daughterboard, and thermal dissipation systems are all different. For instance, the PinePhone Pro’s cameras will not fit into the PinePhone chassis and are electrically incompatible with the PinePhone’s mainboard. Software enablement would also be required to drive the original PinePhone’s components (such as the LCD) using the PinePhone Pro’s mainboard. Thermal dissipation is another important consideration, as the higher heat output may not be trivial to overcome in the original PinePhone’s chassis.

Don't the wiki state the pine phone as using the same screen as the pro?

The wiki does not state that, no.