68Bird400, my rebuilt 400 was running very hot last month, so I bought an aluminum radiator and an electric 16-inch push fan on the front. Previous temps went over 220, but now, in the heat of Tennessee summer, it never goes past 200. In the early morning hours on the way to work (35-40 minutes) it stays at 190 or so. Only in the afternoon sun does it get near 200. BLUF, these blocks run hot and you might as well get used to it, I suppose. :rolleyes: