I thought I should register and post this to add to internet know-how. I've recently installed a spectra cu1453 rad in place of my truck's original single core. I hadn't set out to upgrade it, just ordered the wrong part and realized it wouldn't be an issue to install.

There was no trimming of the fan shroud required, however the mounting holes for the shroud's upper bolts and lower clips were not predrilled in the new rad, so I had to transfer the measurements over from factory rad and drill them. As well, the throttle body coolant return rubber hose was 2" too short to reach the new rad. I needed a chunk of 3/8" coolant house and a splicer to extend it. Hopefully that helps someone!