Are there any aftermarket radiators substantially better than stock.  Are they needed on built motor sumething such as a Halls or Q with  an agressive duner.   I assume more power = more heat,  how does a stock cooling system handle the extra power.  Are you able to "ride" or are ;you always stopping to cool down.

Think anyone that has had an all out HRD or HPR top end has never had a cooling issue. As long as its jetted correctly and head is set up correctly you should never see an over heating issue.

What most folks dont do with the stock radiator is have it serviced, after 20 years there could be need of simple flushing and pressure check, I had 3 done cost run about $45 to $90 depending on what is found and repaired way cheaper than a aftermarket radiator.