453 '61 Super Sports is correct. The number 458 has shown up in print a few times. 142 is the total number (in cars) of production 409s in '61. A total of over 200 engine assemblies were produced before they shut it down due to problems with the castings. Before then, attention was turned to a newer (better) casting for '62 (the 068 block).
IT had none of the problems of the '61 623 block.
Verne
