[LongBox]

If my memory serves me correctly, the first generation Chevy Vans, the ones with the engine between the front seats, came with monoleafs, although many had multi leafs as heavy duty options. Perhaps that's where the spring came from.

My 67 Chev G20 had a 12 bolt posi with leafs and a 4.11. The rear axle was worth more than the van.