Tall deck or not

I just bought a 83 chevy 3/4 ton with a 454. how do i know if it is a tall deck block or not? i bought the truck for the engine to build for a race car. what are the pros and cons of a tall deck?

I think most tall-deck blocks were either 366 cu. inch or 427 cubic inch.

Get the casting number from the block and type it in to a google search to find what it really is.