I have a 400>>499 stroker and I run a Summit 3 row aluminum radiator and dual electric fans. I have the 440 source WP and WP housing and my mess stays cool no matter what. I know people ding the 440Source stuff but so far, I have had zero issues with their cooling parts.

I would recommend that you go with the shroud to really direct that airflow through the radiator as opposed to pulling it from the sides. As stated before, if you are cool while moving but over heating at low speeds/idle, then this is airflow-related...period. You can add all the upgraded radiator/WP/WP housings you want but it won't fix the problem.

Try the shroud first. If that doesn't fix it, might be time to look at a fan upgrade..

A bump in initial timing to 16* or more would also help the cooling overall.