I agree w/ Teach. I bet part of the 3 quart low was from the oil change and measurement error.
I had a similar situation in my Allison tranny, when I did the initial 5K filter change. Tranny selector system showed the oil was 3 qts low, and you lose about 1.5 qts doing the filter change. I am now convinced it was low from the factory.
On the next oil change (every 11k miles for the CAT) check the oil level after about 500 miles and see where it sits.
'07 Winnebago Journey 34H - CAT C7, Koni's, MCU's, SS Bell Crank, Safe-T-Plus
'07 HHR Toad, SMI AFO, Blue OX