they do lower 20mm as the x73 and even lower if need be. There are about 3 inches of play on the perches.. i have the pasm version on our car.. i love the ride.. not harsh at all..Do they lower it the same 20mm as the X73 in the CS and CGTS? Do u know how much adjustment there is in the spring perches? The coils appear to be progressive rate. Is that the case? If I opt for a 3.8L transplant, I need to change my suspension, and these seem like one of the few good options, but I need to know more. ..