Rear seat - spring vs foam

[tomstin]

I have a spring based rear seat and, that I believe has coconut husk backing, is deteriorating pretty bad. And, I think is the root cause of an odor when it rains. A few questions:
1) Are the foam and spring seats interchangeable?
2) Advantage of one over the other?
3) If I keep the spring base, and recover the seat, what should I use to replace that backing? Burlap and some thin foam?

I did recover my front sport seats myself, so I have the hog rings and pliers.

[brutus]

yes there interchangeable.
foam holds up better than horsehair ones
,,, but generally just the front bases that go !
,, ive got a good backing available, but kinda heavy on post ,,
good luck,