I currently have ford racing B springs on my mustang and I wanted a little bit more drop in the front. I was looking into getting H&R SS springs but I only want to put the front ones in because i want the back to stay up a little bit. Is it ok to run two different sets of springs on a car? Both sets are progresive. The rear ford B springs are 200/300 and the HR SS rears are 275/300. Also anyone with H&R SS springs think the ride is too rough? I have tokico illumina adjustable shocks and struts Thanks