whether or not you should modify is up to you. brakes are something you can easily swap back to stock if you ever want to.

i have seen these brackets before, and i would rather spend my money on GM style brackets, and buy a spindle, or machine down my drum spindle to fit them.

the reason for this is they are stronger, and beefier. when you apply your brakes, the caliper really would like to spin with the wheel, but the bracket keeps that from happening. with floating or sliding calipers, there is a certain amount of 'slap' as the caliper moves and hits the bracket when the brakes are applied. the OE brackets go across ~1/2 of the 'slap surface', consisting of 2 parts, an inside surface ~1/4" wide, and an outside surface ~1/2" wide. these aftermarket brackets are only 1/4" wide.

without this outer surface, the caliper will tend to twist slightly more compared to OE, while clamped to the rotor during braking. this can eventually lead to uneven pad wear, and bent caliper slide pins.

i have seen bent slide pins on OE brakes owned by people who apply their brakes very hard and frequently. i would not use these dinky things, though there is nothing really unsafe about uneven pad wear and slightly dragging brakes.., it's just undesireable.