My '37 manual recommends grease between the leafs and then wrap the whole mess in burlap then install a sheet metal cover. This is what the cars had to soften the ride. I bought new front springs this summer for my '37. I ran them about three weeks before removing them to grease between the leafs. The ride was so choppy before you couldn't stay in the seat. After greasing them they rode 100% better. I used a real heavy silicone grease. Joe