A lot of the racers use that screw in style which is I believe what they are, not the press in.
The Cobra Valley ones are a super upgrade for them I have installed on a couple of SPF's.
If you wanted replacements for the 727's they are here, godspeed Bill.
Speedway 1960-66 Chrysler K727 Style Lower Ball Joint - Speedway Motors, America's Oldest Speed Shop