Not sure about the Weld's but I can tell you this. I have my 3rd gen camaro setup for 4th gen spec wheels. I am currently running 17x9.5 ZR1 fronts with 275/40/17 and 17x11 ZR1's in the rear with a 315/35/17. Bumpstop modifcation is required. However, you can't check it with the wheels hanging. If the car is on a lift, the inner part of the lip of the rim will hit against the bumpstop metal. However, once the suspension is compressed, the wheel will also move upwards in the wheelwell, and the bumpstop will be in the open section of the rim, and the only way it would ever hit is if you got the car airborn so the wheel travelled to its ful extent. You can see how this works by using a floor jack under the pumpkin. You have to use the floor jack to get the *** end of the car off the ground, take the rear wheels off, then use a lift to raise the car all the way off the ground.