Bottom line, use the right parts. Why would you use the 73+ spindles when the right stuff is available? There was an article in Mopar Muscle a while back, I no longer have the specs. They printed a chart with different variables between the earlier and later spindles and there were some differences, I think mostly with roll center. BUT, the test was not only skewed from the start with non-factory settings (lowered here, changed there, who knows if a stock setup would yield different results?), it also was very one dimensional - the factory ran these setups through simulations that measured everything seven ways from Sunday. One test will not find every gremlin, the same way that a standard alignment will not find issues beyond the basics.

The right parts are out there, use them.