The original race engine was a nice 351C, modified and with a dry sump system. It sat low in the chassis and was a nicely modified motor. It just need a couple hundred more ponies.
Here's Troy Bowen of FPS as he delivered the new motor.
Dyno runs were impressive.
It ran out of air at the top end, just reaching 700 hp.
But the Nitrous would make up for a lack of air. And add up to 400 more ponies.
Here it is fitted in the engine bay.