You have block casting 10066036 GM crate the dealer told you it was an LT1 is 4 bolt and has raised pistons does anyone know for sure what is?

The casting number 10066036 is definitively not an LT1. The LT1 used a different casting number. A quick search shows that number is associated with various small-block Chevrolet engines, but *not* an LT1. The "4-bolt" and "raised pistons" descriptions don't automatically identify it either, as those features appear in many different small-block Chevy variants across various years and applications.

To know for sure what you have, you need more information:

* Check the engine block itself for additional casting numbers: There are often other numbers stamped or cast into the block besides the main casting number. These can provide more specific information.

* Check the heads: The cylinder heads will have their own casting numbers which can help identify the engine family and year.

* Measure the bore and stroke: This will determine the displacement.

* Look for markings on the valve covers or intake manifold: These might offer clues.

* Consult a Chevrolet engine identification guide or online database: These resources can cross-reference casting numbers with engine specifications.

Without additional information, it's impossible to definitively identify the engine. The dealer's information is clearly incorrect regarding it being an LT1.