I'd be wary of changing the trigger reset spring. Most apply a certain amount of force for a reason.
i don't know how familiar you are with the litigation that occurred causing the firearms industry to dramatically increase the trigger pull weight circa 1980's to avoid liability issues
but that is one of the reasons they put stronger springs in them
i am sure that there are mechanical reasons on some rifles as well
but for me a 7-8 lb pull and a 400+ yard shot is not a good combination and the rifles i have converted are from that time frame for the most part