Is there a Visual way to determine a 327 block from a 350 block?

There are several hints that can lead you to think you have a 327, such as: early 327's did not have accessory mounting holes on the ends of the heads, 2 bbl. 327's usually had the oil filler tube coming out of the intake manifold with no filler caps in the valve covers, some 327's had funny looking harmonic balancers compared to a 350, a 327 2 bbl carb has a smaller opening in the top than a 350 2 bbl. But the best way to tell is to scrape off the crud on the id plate at the front of the block near the passenger side head and write down the numbers. Then go to Mortec.com and see if they have a listing for your number.