I do not manage Truman and I will ask Mike Bayless about the population but Truman traditionally is one of our best crappie lakes in the state. One thing I have found in the last ten years is anglers have become much more self-regulating when taking crappie home. In years when crappie have grown well and there are lots of 10 inchers available, anglers will generally throw back 9 inch fish. When growth is slower and the majority of fish are 9 inches anglers will harvest them. This has changed the need for raising the length limit from 9 to 10 in some lakes in my opinion. Truman has lots of big crappie and is generally viewed as a better crappie lake than Stockton. Crappie populations can fluctuate significantly from year to year but I heard nothing but good reports out of Truman. It might just take you a while to get as proficient on Truman as you were on Stockton. Good luck.