BudsGunShop.com - Stronger spring needed?

The spring will be fine. Under no circumstances ever stretch a spring. They are wound and the metal grain is laid out to work properly. Stretching will interrupt this structure and harm the spring. If you want a better spring when you replace it here's one of the best.
ismi-gunsprings.com/index.php?option=com_content&view=article&id=11&Itemid=16

mark we stretched 1911 springs in the military for over 20 years to keep them working

Not necessary David, However, all my magazins that Wolff makes a spring for have the "Extra Power" +10% Springs. -- gunsprings.com/SEMI-AUTO%20PISTOLS/cID1

HI David, No you're fine without it. Just make sure you get a good magazine with a strong spring.

No you should not need a stronger spring yo may have to slightly stretch the spring however but in most cases even this is not needed