The Cummins Mustang is already crazy, but today we see if it can take every pound of boost the turbo can throw at it. From cold starts to full-throttle pulls, the engine gets pushed harder than ever.

Cummins swapping a Mustang sounds simple until you actually try it. From cutting the firewall to fitting a diesel the size of a refrigerator under the hood, nothing went smoothly. Every bracket, mount ...