Not quite that easy
The mainspring on both of those guns has to be relieved to lighten the trigger pull. The V-mainspring IS the trigger spring in those actions. OEM mainsprings will give you a OEM type trigger pull both in double action and single action. Trapper gun springs used to sell a spring set for the D frame guns which includes the diamondback that claimed it would lighten the trigger pull but I didn't really notice much change in my gun. But back then I didn't have a trigger pull gauge either. With the Python when you lighten the mainspring and shorten the bolt spring for a lighter trigger pull, you also lighten the hammer blow to the primer and can have inconsistant ignition with some .357 ammunition especially in double action. One can alter the original springs in either gun themselves, but if you go too much then you will get misfires especially in double action. Then having an original mainspring on hand to get it back into firing condition would be desirable. For someone who has never taken one of these guns apart, it would be advisable to get the Colt DA shop manual volume number 1 to understand all thats involved.
If you wanted an original mainspring for either gun, Colt should be able to supply them.