Some 120Y's came with a plastic shroud that fitted to the radiator. It was a 2 piece. If you could find something like that, & fit say the 10 inch fan from an N12 Pulsar so air was drawn from the whole radiator, it'd probably work well. Something I was going to try with my B310 Sunny was get a fan sender from an N12 Pulsar & mount it in the head opposite the temperature guage sender. Most later A series heads have a fitting that is part of the emissions control, I was going to use that outlet, with a relay to run the fan. That way the fan is only running when the engine is hot.