[olredalert]

------Is it possible that the numbers you see were stamped after an inbetween decking job? Therefore you still see the remains. If you are racing a 1973 dated 4-bolt main block the engine didnt come out of a car anyway! I believe it would have to have been over the counter. As far as I know 4-bolt applications were discontinued after the last LS6 1971 Corvette. Truck or passenger car or Corvette 454s produced after 1971 should have only been 2-bolt mains. I had several 1973 dated LS6 engines we used to race with.
------As a matter of fact,my old race car Red Alert(now in the capable hands of Mike Guarise) has a 1973 casting date LS6 block in it presently (original engine was included with sale)..........Bill S