The J39 was a later development, exchanging the J38's 4 ft 8 in (1.422 m) driving wheels with larger 5 ft 2 in (1.575 m), 289 J39s being built. Some of the J38s were later rebuilt with J39 boilers.
All J38s were withdrawn between 1962 and 1967, with the last two in service being No. 65901 and No. 65929, they were also the last Gresley locomotive to be withdrawn. None survived into preservation and all fell victim to the cutter's torch.[1]