Exhaust manifolds are different (?? maybe only at the manifold to head interface as different heads were used 57 to 58 ??) between 57 and 58, but I agree with Buckshot that the 57 pipes are probably as close as you are going to find (assuming Napco doesn't get in the way). It isn't to late to do this if the engine is still accessible.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
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