03-04 cobra driveshaft will fit any 96-04 sohc/dohc car with a t-56. The rear pinion shaft mount will need to be changed to an 03-04 cobra piece if using solid axle or 99-01 IRS, if using 03-04 IRS then there is no need to swap pinion shaft mounts. Or you could change the rear u-joint to a hybrid piece.
The 03-04 cobra driveshaft is shorter so thats why you cannot use it on cars with t-45/t3650 trans.