Yeah but I took my stock arms off years ago, cleaned them up, had my local shop press new bushings in and I put new ball joints in, painted it all up. Cost me over $50 a piece. 1 year later one arm crack and almost rip the ball joint right out, now a few years later the other stock arm has play somewhere--top of the wheel moves a good 1/4 inch. The spc arm on the other side is still tight as new. Has grease fits also that allow you to re-grease them.
Stock arms are cheaper but if you drive your car hard they seem not to work so great.
I know costs add up but looking back sometimes doing things the cheapest way doesn't always pay. Unlike putting in a Chinese stroker crank, these tubular arms are better every way over the stock arms. Stronger, last longer, are easier to adjust. Its like using electronic ignition over points.
But yeah back in the early 80's many people were still using points cause in the short term it was cheaper.