454 inch small block chevys???

For the most part, 410 sprint motors are running a big bore and short stroke type setup. Usually they don't run anymore than 3.875 stroke. Bore is anywhere from 4.125 to 4.155.

 

The '70's big block was the LS-6, and the 350 was the LT-1. Note the lack of hyphens in the modern LS6 and LT1 designations. Easiest way for GM to "cash in" on the legendary monikers, but still differentiate the modern engines from the earlier models.