well...
without actual details of the cooler, current oil, operating temp, ...it's hard to give any advice.
since i'm not that 'at home' in the oil-cooler stuff, i've done some research concerning the matter...
all say that you can't just change the cooler but need a complete 'system', which means that a thermo is a must. otherwise you could do some damage to your engine.
not just any thermo, but one specificly for aircooled bigtwins, since there's a difference in working temp.
changing oil is not an option, cause not only will your low-temp lubrication change, your high-temp lube changes too.
you should already have oil that has the specific characteristics to run in an aircooled high performance twin.
options for you could be:
- easy mount oil filter adapter with internal thermo:
click
- jagg manual bypass valve:
click
for a complete option, supercooler with built-in thermo:
badboy cooler for buell
i would also suggest an oil-temp meter.
for the pump...it should be able to handle the specific aircooled highperformance twin oil in it's coldest and warmest working temp.
helping the oil cool can be a good thing with a complete system, but going from a 6 to a 19 row is maybe a bit of overkill???
all depends on use ofcourse...
hope this helped