Chevy Big Block Casting number help.

[RichSchmidt]

The 289 casting is basically the successor to the 512 block. It is a thick wall casting,and was available in 2 or 4 bolt. I had one in my race car with 2 bolt mains and studs .060" over making just a tick over 600hp@7300rpm on motor and a little under 1000 hp on a 350 shot of nitrous. The block held up fine,and it eventually threw a pair of Manley rods out the side after about 700 runs,about 100 of which were on nitrous. The 289 block was used in trucks,vettes and hi-poi cover the counter engines.