Again, I think this is gonna really depending on the type of brakes used. let me break it down for you:
You have 2 kits, say both are at 60 inches hub face to hub face (using stock style hubs)
Kit A:
Used brakes and hubs that add .75 inches to each side from a stock hub style for a total gain of 1.5 inches, you are now at 61.5 inches hub face to hub face, where the rim mounts
Kit B: Exact same kit, same builder. However this one uses brakes that use an offset hub (wilwood narrow 6Rs specs), bringing the hub back to a 0 inch gain. You still have a 60 inch track width.
Now where it really gets interesting is I've found there are kits that actually have hubs that are negative on offset and thus narrows the track width, wilwood actually advertises them on their web site.
Regardless, there are a lot of brake kits out there from various manufacturers, some list the track width gain or loss and others don't. So unless we know that offset number, we can't accurately say one kit is narrow or wider than the other.
