NOS 3.51" mopar stroker crank in a 318?

Rocket said
Piston companies like Diamond and Others can make custom Pistons for your needs. Last I checked Racetek (not sure if spelling is correct) was reasonably priced.

cool but how do i know what to ask for as this is an off the norm stroker crank? Do I just tell them the crank is a 3.51 stroke, 30 over boar 340?