302 and 351W also have different oil pans. 351m/400m heads are all open chamber style as with the 351c 2v heads. All 351m's and 400m's are considered open chamber and can be swaped with 351c 2v heads. Some 351c ho's had open chamber 4v heads. 351c 4v "4 barrel carb" are closed chamber heads. So are the Aussie heads. The later 400m had hardened exhaust seats. 351 windsor has a taller dizzy than a 302. 351c/351m/400m have a 429/460 style dizzy. 351m/400m have 429/460 style bell housings. You can swap 351c 4v/2v, 351 Aussie 2v, 351m/400m heads on a 302 or 351 windsor block. You need to modify the water passages, and either use a Street Boss/Track Boss intake, or use adapter plates for windsor style intake maniflods. Plus the piston issue. Silvolite made a special piston for either the 351W or 302 swap. The cheap way on the 302's was to use a 289 rod and Boss 302 pistons. Boss 302 rods and 289 rods are the same lenght. 302 rods are different.