You are correct, there is a 454 tall deck around 79-82. I assume it's likely the same block as the 427 being the bore is the same. As stated, the tall deck blocks don't come in anything that is one ton or smaller though.It most likely isn't a tall deck engine. They were used in the big C-60 type trucks not a C-10 or C-20. They were 366, or 427 ( Ihave heard rumors of 454) cubic inch and look the same as a normal engine at first glance. The intake is wider and often has two thermostats. The distributor is about an inch taller also on some the best I remember. I have been told both they are the same length and that they are different. The deck is higher and because of that there is about 1/2 more material above the water pump holes than a short deck engine. That book will explain the difference better than I can. Once you see it in pictures thay are easy to spot. If is apart they have TRUCK cast into the block and heads. The pullies are also different for the C-60's. A truck engine will often have double groove pullies the best I remember. The C-20 alternator bracket I used to have was a large squared off piece with a brace going back to the intake.
The tall deck engines used to be used to be popular for stroker engines years ago. The crank and rods are usable in a normal car block the rest isn't much good for anything else.