you did not post the centerline of the old and new camshafts. But with just 9.5 static compression, the increased duration killed a lot of dynamic compression. You most likely lost a lot of torque on the low end and that is why the converter is not stalling at the same level. Run a compression check with the throttle blades open and see what the static compression is, if its under 140psi, you might try advancing the new cam to get some of the dynamic compression back.