Gee Joe, what brand of a motor do you have?

IF it happened to be a tall deck Chevy late model big block, the deck height
moves the heads upward and outward. The intake manifold (where the distributor mounts) also must move up and get wider.... MSD makes a tall
deck distributor BUT some intakes are cut lower for a standard distributor....
you gotta know which intake. My suggestion is to call the intake manufacturer and ask their tech line. Better than buying the wrong dist.