The early scion radiator looks like a better fit in the nose as it is wider, more efficient with a larger core, and has no filler so it should fit better vertically without tilting in the nose, so less restrictive to airflow. You'd fit a vw shaped expansion tank behind the motor that plumbs into a heater fitting on the motor to fill.
The scion rads are about $70 for a two row so a little more expensive than a two row civic and the scion is not available as a three row, but the larger core allows for a 14 inch fan instead of a 12 and the two row probably holds almost as much coolant as the three row, small core civic.
It has pin mounts top and bottom so easy to fab brkts with flat strip and grommets.
Just looked at Jack's site and it appears to be a perfect fit to a 20 inch wide (at the bottom) nose!
https://www.kineticvehicles.com/noses.htmlThe scion rad has the bottom pipe on the right and the top on the right and angled where the civic is more centered. The brass pet c*ck is on the bottom.
14 fan
https://www.ebay.com/itm/Derale-18214-1 ... SwVNNcLPzUscion 04-07 rad
https://www.ebay.com/itm/FOR-04-07-SCIO ... Swf35c-bVSVW expansion tank with cap
https://www.ebay.com/itm/Radiator-Coola ... 15580bac2c