Shorty pistons are gonna have a lot of rock in that short bore. The reason 3.58 was the most Chrysler could push it and live a long life.
Couple that with the increased side loading from the longer stroke.
None of those things are really an issue. The taller deck of the Mopar is still better than the chevy. I think the problem is the things run so well they get hammered on a lot. The blocks are not that great so things move around a bit especially at 7000 RPM and that is where the problems come in. If you were to build a lower RPM torque engine for a truck the reliability and longevity shouldn't be an issue.
