Our '71 project has correct buckets (although the car originally had a bench), but I don't care for the covering and I've begun to notice that they pretty sacked out spring-wise. Is it a major pain to re-do the seat's suspension, springs etc. or should I consider a seat swap. Now for the big question! WHAT OTHER KINDS OF BUCKETS WILL FIT IN A '71 MALIBU???? Thanks.