I don't believe so. Most of the lowering springs out there for the 03/04 cobras are designed specifically for the IRS. $75 is a great price for H&R's but I wouldn't chance it.
I remember when I bought my H&R Super Sports for my 03 the description was for 99-04 v6/GT/Mach 1's, no cobras because of IRS.
12 Black GT500 SVT PP l VMP TVS l JLT123 l O/R X l 28x11.50Rx15 M/T Street R's l BMR Suspension l Recaros
03 Sonic Blue 3.8 / 17 Magnetic Fusion Sport 2.7 EB