Last to implement a smog/air pump too.
The wedge chamber is good, coming from that era, but then then someone brought the chamber back to a rendition of the earlier 273 stuff and brought the open side to a more squarish shape and then called it a magnum. I wonder but then don't...which was cheaper, then, making a new piston shape or casting a new head...they answered that already I guess, 3 head designs later!