Ls6Camaro

Hello all, new to the forum, looking to figure out the one thing that is stopping me from enjoying my 1968 camaro... we have replaced and upgraded everything, my big problem is steering, the car drifts to the right every now and again, and bumps steers. have done about 3 alignments, the steering is nice and tight, just don't feel comfortable with the way it pulls or jerks during driving, was contemplating a rack and pinion, but really didn't know what direction to go in, I've been seeing folks using other methods was hoping i could hear from you guys. Thanks again, look forward to being able to learn and also help others on here.