[767Jockey]

El,
That double puller fan you mentioned sounds promising. While the extra CFM it pulls can't hurt, I am more interested in the additional area of the radiator that it forces into use, much like a big puller with a properly designed shroud would do. I remain convinced that your problem is in the radiator size and shroud design. The problem got worse when you blocked more of the radiator with the faulty shroud. It should get better when you call more of the radiator into proper use. This seems to be the only change you've made that had any documentable difference to the problem. This is certainly the road I would go down. Best of luck.