Not alot of benefit in horsepower, but every little bit helps. I wanted full flow oil filtering which is only available on the 58-62 261. I just had my 235 machined to match the 261's full flow system, so its not hard to do that.
My plan is to go with a dual pulley HB for the accessories. I am just going with AC, not PS, but I can't see ANY benefit in using a dual pulley on the Alternator or AC Compressor. The power comes from the crankshaft, not a series of belts. Although, lots of people do it that way without incident.
Smaller Pulley makes it turn faster, not slower? Its why Dave suggests not using the larger HB with his water pump adapter. Overspeeding the fan is not a good thing. I am doing it anyway to see for myself what the difference really is.
