I am using a Griffin, it is the one they list for a 87 GN. the core is a double row that are 1" each. With the Spal full size double 13" fans it stays cool. it will get to about 160 at the starting line and 180 when I get back to the trailer.. When I first put the 455 in, it kept running hot, I tried taking the thermostat out but no help. Then I installed a bleeder in the intake manifold, in one of the holes supplied for a sending unit highest one on the manifold, with the bleeder open I fill the rad until water runs out of the bleeder, close bleeder, start the engine put rad cap on after warm up open bleeder until water comes out. Done.. cured running hot.. :Smarty:
I tried...in order if i recall correctly... F-body rad: OK idle, constant temp climb at highway speed Custom Copper 4-core:Constant temp climb Griffin 2*1": Constant temp climb - slightly slower Move the trans cooler to external: Constant temp climb - slightly slower Bracket in airflow with baffles: Better, still climbing after 20 minutes on the highway. ...and finally the Griffin 2 * 1.25 : SUCCESS! ...one vote for the Griffin. Great product there.