the stock 84/85 radiator is significantly smaller than the 87...i'm not sure if the rc fans will fit.i have the dual spal fans and i'd say they wouldn't have fit on a stock size radiator.
i recommend swapping in a new modine v8 radiator,they are cheap(~$100 at autozone) and big.you will need a larger radiator holddown from a v8 car.
later,sean