I assume you mean the return spring under the dash; I haven't ever really had a lot of problem getting them connected however if your clutch is all adjusted and you are having issues, it may have to do with the adjusting rods. That spring is there t bring the pedal back and to keep the weight of the clutch linkage from applying pressure to the throw out bearing (which cause early failure or was thought to). If you hard having problems getting the spring on, IMO you have an adjustment issue; if the clutch linkage is all connected but the clutch isn't adjusted, then you need to adjust some "slop" into the linkage which should give you the distant you need to get the spring on.
70 Challenger RT 440-6, 73 Cuda (under const)
05 Durango, 99 Dakota, 01 Ram 4x4, 14 2500 4X4, 10 PCP Challenger RT, 01 Viper GTS ACR, 52 B3B w/330 Desoto Hemi, 70 Hemi RR, 61 Jeep FC170
9 x Challengers. AAR Cuda, 4 RR, 2 GTX, 4 Chargers, etc... (too many to list)