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They rot from the inside out, if they are real soft replace them why risk it?
Summit sells some neat ones they are a silicone like material. Different colors, use the clamps made for them not the auto parts store type
31 years is a long time. It doesn't take much time or effort to replace all the hoses and is worth the piece of mind. Obviously, flush the block while you are at it.
I would say YES, cause in time will start to leak, and leave you stranded.
My C6 2005, still has it's original hoses, and the bottoms hose started leaking like you turned on water hose.
So I would say you are driving on borrowed time.
I was fortunate to find some GM hoses for my '84 a few years ago but most of them are no longer available. I had mine replaced prior to doing a trip with the Corvette Museum in 2008 when they were 25 years old. Saved my originals.