Mixing branded parts that were not meant to be pieced together might be the problem. I checked on the Helix website and they do not give very much of the specific details on the control arms, BUT, under the description of the A-arms it does say "Feature: Improves Suspension Geometry" which typically indicates that these arms are not the same as the stock pieces. I see that they seem to sell a kit having the 2" dropped spindles which would put the tire higher up into the wheel well which would most likely eliminate your tire rubbing problem.
Some kits use the taller Camaro or Big Car spindles to operate correctly. Again, could be you do not have the correct and needed parts to make this all work.
Later Pontiac rims which are 14" and designed to fit front disc brakes will fit. Earlier rims such as the original ones on your car will not. This has been covered on the forums a number of times. I have a front disc brake conversion on my '68 Lemans project and the stock 14" rims will not fit, but grabbed a set of later 14" rims made for
disc brakes and they fit just fine. I believe they are also deeper, ie wheel back spacing which can also be something to look into to eliminate the tire rubbing.
I suggest you go on the Helix website and they do have "Live Chat" as I was hit up with it when I was searching for info. Talk with them directly and I would think they would know exactly how to solve your issues rather than guess or become frustrated with the set-up. It is important to have all your parts matched, a-arms, spindles, spring height/rates, etc. or you may find yourself with an evil handling car that may let you down at the worst possible time and put you off the road at best or in a tree at worst. Don't just guess and piece things together because it was a "deal." Get the answers from the experts who made the parts.