Yes traction bars and ladder bars are very different. Your 73 has coil springs in the rear and traction bars are for leaf springs ( although they do make some for coil springs ). Ladder bars will require welding brackets ect..
If your having wheel hop problems your springs, shocks and control arm bushings may be shot.
I used Impala HD springs, boxed upper and lower control arms, poly bushings all around and hop stop bars ( they go between the upper control arms and the housing changing the geometry ) in my 70 with a healthy big block and have no wheel hop problems. They should work on your 73 as well.
i just put polyurethane bushings and boxed the rear control arms last augest when i put the 496 in and i still have wheel hop problems.
the problem is they don't make anti hop bars for '73-'77 or i would use them.
I'm not 100 % sure but the no-hop bars for a earlier year (70-72) would fit in your 73. I think as far as the upper control arms go they would be in the same position, again I can't be 100 % sure. I have a 76 Laguna that I can check and compare to the one in my 70 if that would help you. It could be the rear springs worn out also ( I didn't notice where you replaced them so if you have please ignor that part)
If none of that will work for you I would try going to 73-77chevelles.com there are a bunch of G3 owners there and several that race they should be able to help you out.
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