I'm using a rad and single fan from a 305 tpi for my 5.7 tpi. I have the 5.7 rad and dual fan but it won't fit my 86 z28 (took off an 88 GTA) The coolant is 50/50 I'm using a fluidyne adjustable fan thermo set to click the fan on at about 160f. I also have a 180 thermostat. I'm thinking about running just a restrictor in the water neck and an auxillary trans cooler in series. I'd rather over cool than overheat.