My LS-1 project went south when I found a crack in one of the cylinders. So, I am going back to my de-stroked motor. As for the 400ci block. Do they make a 400ci block, or do I just bore out a 350ci to achieve this? Reason I am asking is for the motor mounts.

 

You'll need a 400 block. They were found in 70's impalas/trucks/stationwagons.

Try to find one that hasn't been bored. They are getting real rare and kinda pricy in some areas.

 

Check local machine shops. I found mine there, and I got the block for $300 as long as they did the machine work...

Ends up $700 total after the machining.