New motor/1050 dominator won't idle

Started my 5.7 hemi based 414 stroker for the 1st time today in 45 degree weather. The 1050 Dominator from Pro Systems carbs did eventually startup, but the motor won't idle. Have to run the idle screw all the way in to get the motor to run at 3000rpm. If I back out the idle screw even a little bit it dies. I'm thinking I need to try opening up the idle mixture screws since the temp is 45 degrees. There is NO vacuum port anywhere on the carb or the intake, so I guess I'll have to go by ear/rpm.
Any other suggestions? Does it seem like I'm on the right track?