You may be tempted (as we were) to reuse the pulleys from the old 351M/400 engine you're replacing. Don't! They look right, but the center pilot hole for the water-pump pulley is too small at 12-inch diameter--even worse, none of the belts will line up with the various accessory drives. Use pulleys from a 460 (58-inch pilot hole) or get these nice aluminum ones also from L&L Products. The two-sheave water pump (043842) and the four-sheave crankshaft (043854) pulleys are necessary if you're running the A/C compressor.