Welcome 74Stingray!

Thanks everyone for the warm welcome!  Someone asked about my plans for my '74.  Well, my first item to tackle is the heating issue, and I am hoping that I can get some good info to build on from everyone's experience here.  The car has a 400sb engine and a relatively new radiator with dual electric fans.  The 400 does have steam holes drilled in the heads.  I have driven it multiple times since purchasing about a month ago, and have seen overheating occur 3 times.  It has done fine at higher speeds with good airflow, but below 40 mph the temp rises above 200 and ultimately above 230/240.  Based on my research thus far, I believe airflow is a problem, and I also may need to consider upgrading the radiator to an aluminum (i have heard a "Be Cool" is worth considering).  Anyone have any suggestions / experience with cooling a 400 sb?