The inexpensive option is the N14 or S13 radiators -- less than $100 new in USA. And it fits the engines. It's about the same size as the Maddat radiator. It can fit in the unmodified engine compartment, though most choose to cut the core support to let it sit more upright and open up more airflow to it. It comes in thin (CA18DE) and thick (SR20DET) versions

Most also choose to install a very large front-mounted intercooler, however remember that WRX uses a small water-cooled intercooler so you know it is effective. Maybe you could fit a narrower late-model OEM radiator alongside a small intercooler to the side (using the A/C opening), both behind the core support. Late-model radiators being aluminum are much cheaper than the superior copper designs. Almost no one uses copper anymore it just costs too much

CA18 stock OEM radiator in B110

Attach file:

---

  Maddat RI003.jpg (94.85 KB)