EASA accepts alterations on non-critical components that are substantiated via Form 337, as detailed in the EASA-FAA Technical Implementation Procedure (TIP) rev 5, paragraph 184.108.40.206 EASA Acceptance of FAA Alteration Data:
“Except for alterations on critical components, FAA-approved or accepted alterations per 14 CFR Part 43 installed on a used aircraft exported from the U.S., regardless of the State of Design of the aircraft, are considered approved by EASA at the time of import to the European Union. EASA shall accept such FAA alteration data when substantiated via an appropriately executed FAA Form 8110-3, FAA Form 8100-9, FAA Form 337 or logbook entry.
Alterations on critical components must be EASA-approved via STC, in accordance with TIP paragraph 2.2 (Design Approval Procedures for Supplemental Type Certificates (STCs)).
An FAA STC whose installation is documented on a Form 337 must be approved by EASA in accordance with TIP paragraph 2.2.”