You never said if the vortecs were modified from stock to allow more than 0.450" valve lift.
If they have you may want to consider the Comp Cams 270HR. Using their Camquest software configured for your combination it indicated 404 HP and 463ftlbs of torque, firstname.lastname@example.org" lift single pattern cam, 0.500" valve lift with 1.5:1 rockers. Should work good with your torque convertor.JMO
You may want to upgrade your valve springs for insurance.JMO