by shytebucket » Mon Jul 09, 2007 8:32 pm
John B., just switching to the Buick v6 you could expect to see water temps of 170 average and 220 peak with your old cooling system (assuming 100 degree weather).
If you find an OEM v6 radiator and fan/shroud that fits the Vega you would be in good shape. But, if you're not absolutely set on a V6 swap I would do what it takes to get more airflow through the core.
How are the two fans mounted up front? The fact that you had to add a blockoff suggests the flow from the fans isn't fully going through the core. Are you using a short water pump? It would even be worthwhile to go to a thinner core to make room for a fan. Or trimming the core support enough to make room for a larger fan in front.