I would for sure use the OEM 7 blade 19.5 inch with factory thermal clutch and use the baffles top and bottom if you have A/C, they do make a difference and I would also use the smaller Water pump pully (6 1/2) along with a Flow Kooler water pump. Make sure the plate between pump and timing cover is as close as possible to the pump. There is a link to that HERE They all make a big difference when put together and helped me out a lot with my cooling problems. I also put a 3 row alumn radiator in since my stock 4 row was shot. Now before I started my rebuild my temps stayed at about 10 degrees warmer than my thermostat in NC summer humidity and it didnt matter if I had a 160 or 180, so now I will run a 180, since in the winter time the 160 was too cold.