I have a Chevy Silverado one ton dually. I was wondering how to determine if it has a tall deck 454 v. short deck 454 without tearing apart the engine. Anybody know tthe answer to this puzzle?  

Well im not one to really hive advice because i dont really know much but you could try running the casting number at http://www.mortec.com/bbc.htm  

amount of meat above water pump hole is about 1/4 versus 5/8 inch.  4 rings on piston.  4 bolt main.  

Not positive but i think all tall decks were 427 or 366 . Im also thinkin they were only put in the big comercial trucks too. More than  likely you have a standard deck 454. The distributor is much longer on a tall deck too.