[Killer_Mopar]

I took the seats out of my dads car(70) today and was well aware of the fact that the passenger seat was not original and the other seat only half came from the factory in 70. The drivers seat back looks to be original(horizontal inserts) but the seat bottom looks to be a 71 or later version(verticle porousl inserts). The passnger seat looks to be a 70 Cuda seat(verticle insert). My question is, will the cuda seat and later challenger seat bottom work fine with 70 skins and seat buns???? and when I looked at the seat bottoms the springs on the bottom of the cuda are totally different and look a lot more sturdy. Is there a way to make the later seats more sturdy? as the original one has a broken spring.