Motor replacement part number?

what is the motor replacement for 7-164304-24?

Your replacement single speed motor for the 7-164304-24 would be the 5223X. You can also use seal kit GOKIT2 for a standard chlorine swimming pool and the GOKIT2SALT for a saltwater swimming pool.

What would be a comparable new pump/motor replacement?

The complete pump replacement would be the model W3SP3015X20AZ.

How about the Purline PL2603?

I would have loved to recommend that pump but unfortunately, we are out of stock on those with no confirmed lead time.