For everday driving the nickel content in the block doesn't mean a thing, if it is anything other then a rumor!!!! If you're going to build a racing Windsor, it doesn't matter much either as both blocks need some block filler to stabilize the bottom end of the cylinders. For an everyday driver, Ireland's Child gave you the good low down. Get a good set of heads and a mild cam along with some quality pistons that will yeild around 9:1 compression with cast iron heads or 9.5 to 10:1 with aluminum heads. If you want to pop the bucks, go for the whole Edelbrock Performer RPM package, cam, heads, intake, and carb. It's a proven package where all the components are designed to be compatible and it works very well for a street engine...