* The original block casting: Different castings have different wall thicknesses. Some are more robust and allow for more boring than others. You'll need to identify the specific casting number to determine its bore limits.
* Desired piston size and stroke: The bore size directly affects the displacement. Increasing the bore will increase the engine's displacement. You'll need to consider piston availability and whether you want to change the stroke as well (which requires a crankshaft change).
* Cylinder wall thickness: Excessive boring will thin the cylinder walls, making them weaker and more prone to cracking under stress. There's a limit to how much material you can safely remove.
* Cost: Boring a block is a machining process requiring specialized equipment and expertise. The cost will depend on the extent of the work and your location.
In short, while it's *possible* to bore a 454, it's not an unlimited process. You should consult with a machine shop specializing in engine rebuilding to determine the safe and practical limits for your specific block. They can assess the block's condition, identify its casting number, and advise on the maximum bore size before compromising the structural integrity of the engine.
