Early Chevy 283 HI-PO block cast in Canada..... very thick walls , block tanked & magnafluxed , STD bore.
THIS BLOCK CAN BE BORED TO 327cid dia and was by GM
Here is casting # & ID of block
#3789817 GM 327 / 62-65 Passenger,Chevelle,Truck Sm journal
Also 283 FORGED crankshaft STD/STD.