LA heads will bolt right on a Magnum block and vice versa. If you luck into a 5.2 block, you can bolt on your choice of LA heads, still be able to reap the benefits of the hydraulic roller lifters in a Magnum and have plenty of good choices of LA intakes. You will need to use custom pushrods for oiling the rockers, but that's no biggie. 5.2 Magnum rotating assembly is internally balanced like a 318, but a 5.9 Magnum is externally balanced....and much different than an LA 360. You would just need a 5.9 Flex plate or flywheel if you go with a 5.9. Most any 5.2 or 5.9 Magnum you buy out of a truck or van will still have crosshatch showing in the cylinders, so that is a plus.