Is this true

We've sonic tested several 70-73 date coded 360s and all of them measure about twice as thick as the later 70s engines. Hensley Motorsports sells 408 strokers based on .090" over 318 blocks so obviously, it can be done. We have a Dakota Ultrasonics tester that cost about 2500 bucks and it's accurate. So far the rumor seems to be holding up.