QA1 7740-374 LS Engine Mounts, C10 Crossmember. For use with QA1 K-members Multiple engine swap options available Made in the USA. QA1 63-87 C10 LS Engine Mount Kit. Processing begins as soon as an order has been placed, therefore we cannot change, cancel or modify orders once they have been confirmed. Most e-mails are answered within 24 hours, including weekends and holidays.