No, this is a GT500 item that can be installed on the GT350. The oil/air separator is $400 alone ... a bit pricey. I believe it was determined the GT500 required the separator due to sucking in oil during hard cornering while testing.
Was looking through the new Owner's Manual for the 2020 GT350 and came across recommended oil for 2020. The first is Ford is now says 5w50 oil must meet the WSS-M2C931-C spec OR that it meets API SN requirements. The second part is that in cold temps it is recommended that a 0W40 oil meeting...