DBR3
Aston Martin used a chassis initially meant for the DBR1 to construct a car known as DBR3, and given the chassis number DBR3/1. The car was different in that it used Aston Martin's newly designed 3.7L (3670cc) Straight-6 from the Aston Martin DB4, destroked to 3.0L (2990cc). The car was used in only a single race in 1958 before it was deemed uncompetitive. DBR3/1 was thus given a normal Lagonda Straight-6 and rechristened as DBR1/4.
Read more about this topic: Aston Martin DBR1