Look at the intake and exhaust ports. Then look at the modern 318 ports. Those engines were great as low rpm motors but anything else I would say pass.
56 Plaza 63 D100 step side 67 Coronet, 68 Roadrunner, 69 Super Bees, 69 Coronet 500 convertible, 70 Roadrunner Post, 79 D150 360, and a severe case of Mopar a,d,d
