I've heard you can stretch them to match by airing them up to 40 or 50 lbs and leave them out in the sun on a hot day. Of course hot days might be difficult to come by this time of year.

33 Plymouth Roadster - 383 - 5.90 1/8th 9.58 1/4
68 Dart - 340
66 Belvedere - 400

Windy Hollow Garage - https://www.youtube.com/@windyhollowgarage