sgtar15,
Before you start changing out your recoil spring, you need to find the ammo that works best for you. Then you can change out the spring to a stiffer one if needed. If your shooting light loads, a stiffer spring is only going to make the gun jam, due to lack of force by the light ammo.
Also, if you change out your slide spring to a stronger one, then you should also change out the firing pin spring. This is a must on a pistol that does not have a firing pin lock, such as a colt 70. The slide will be coming back faster and the standard firing pin spring may not be strong enough to retain the pin back, this could cause a slam fire.
The one thing that you might do is to change out your rod to a full length rod, and add a shock buffer. The new rod will cycle the pistol smoother and the buffer will lessen the slide blow the frame. If you check around you can find a one piece rod for under $20 and pads go for 6 @5.99. Remember to change out the pads when they are chewed up.
If you reload, I have found a load that works in wide range of pistols using the stock spring.
185 semi wad cutter, 4.2g of clays powder, Standard pistol primmer.