Only a couple of the aftermarket A-arms use Heim joints, the rest use poly or hard(er) rubber bushings similar to factory... I installed a set of QA1 tubular A-arms on my cousin's 1971 Satellite and they had stiff rubber bushings and a big upper ball joint just like stock, I have no concerns with their strength for hard street use.
Also the Green Brick was built over a decade ago, like others said the aftermarket has come a LONG way since then and a lot of those "home-made" upgrades can now be purchased instead. Still great to know exactly what was in the car though!
