Will this bolt straight in without any modifications?

Yes. This radiator uses factory mounting brackets and connection ports—drop it in place of your original and reconnect the hoses. No fabrication or adapter fittings required.

Do I need to drain the coolant system before swapping this in?

Standard practice: drain your existing system, remove the old radiator, clean the mounting area, then install the new unit. Refer to your service manual for coolant capacity and bleed procedures specific to your vehicle.

Is this compatible with the transmission cooler lines?

This radiator is built for the 3.6L automatic—it includes the transmission cooler passages integral to the unit. Reconnect your existing transmission lines as they were on the original radiator.