Not me, resonance in the small tube will be far more beneficial than the large tubes. If you did an area under the curve for your engine with both types I would imagine you will see that the long tubes low rpm advantage extends far enough into the intermediate-upper rpm range that you end up being farther ahead. Depending on the short tubes length you may never realize any resonance tuning at all until stratospheric rpm levels like 10 000 rpm!
Shorty headers are OK for flow but resonance tuning is why you install a header, actual flow numbers are only a small part of a headers function...also 1 5/8 is not that small...we are talking an 1/8 of an inch here folks?
Equal lengths ensure that any tuning that results occurs at the same point in the rpm range on all the cylinders, it is definetly a goal worth pursuing as it concentrates the resonance bump in the power curve instead of spreading the resonance "zone" across the rpm range....but...if the difference in length is a couple inches at best then I doubt you would see much difference.
I say go for the unequal length 1 5/8" and enjoy your truck and it's unimpedded turning circle.
This will be a street vehicle right?