If you're looking to increase the displacement of your 350 small block Chevrolet engine, one option is to bore it out to 383 cubic inches. This can be accomplished by boring the cylinders out .030 oversize and using a 3.75-inch stroke crankshaft. With this combination, you'll end up with an increase of approximately 33 cubic inches over a stock 350 engine.
One thing to keep in mind if you go this route is that you'll need to use pistons that are designed for a .030 overbore. You'll also need to use cylinder heads that have been machined for clearance with the larger pistons. Depending on what heads you're using, you may need to have the valve pockets modified slightly for clearance as well. If everything is done correctly, boring out your 350 to 383 cubes is a relatively simple and effective way to add some extra displacement without having to start from scratch with a new block.