I don't remember the before & after weights. A couple pounds maybe? I've been running these things for quite awhile with plenty of street miles and many "wheels up" launches at the track. They are plenty strong enough. No worries what so ever. I didn't plate the area where the T-Bar adjuster was due to not knowing at the time how much room I needed for the adjuster, and once I got them on the car I was going to measure and then take them back off and add a plate to box them. Never did though and again, not sure it needs to be, based on the abuse they've already taken.