Jim,
Why are his numbers showing a much lower rpm than reality? The math is simple, based on his inputs, his calculations are correct.
He is using 30 inches for his tire height
He is using .72 for his fifth gear
You show some smilies with a link to some calculations that you made with 28.5 inch tires and a .74 fifth gear (effective running a lower gear if the rear ends were the same in your two trucks).
And, you are running a 292 which is a lot more power across a wider range than a 235 so you can get away with a higher (numerically lower) gear.
Not sure how that will set Dave straight or that he even needed setting straight, he asked for suggestions and personal experiences.
I'll take a stab here and say that based on the info provided by Jim and assuming he is happy, he thinks should go with the 3.73s since his truck uses shorter tires (lower gearing) and has a more powerful engine than your 235.
Chris
