From making variable geometry turbos do the impossible to taking an Allison transmission into the 8’s, Danville Performance’s Mark Broviak loves a good challenge. But to pull off the latter feat, he traded in his love of VGT’s for a fixed geometry unit—the biggest S400 we build here at Stainless Diesel. It’s coined the Godfather and it harbors a 5-blade compressorwheel with an 85mm inducer. Having spent time with our S485 on the engine dyno, where it holds the highest S400 horsepower number at Danville, Mark was eager to try one out on his Duramax Pro Mod, a sub-3,500-pound two-wheel drive race truck formerly owned by Hollyrock Customs’ Mike Graves.


Sitting up against the 3,000-rpm stall Goerend converter and with the aid of a little nitrous, Mark brings the Godfather to life surprisingly quick during staging. Once he leaves, the five-speed Allison from Limitless Diesel makes just two lightning quick shifts before the end of the track, which means it leaves in third gear. To date, Mark has cut a best 60-foot of 1.27 seconds, run 5.54 in the eighth-mile, and gone 8.73 through the quarter—all records for an Allison-shifted truck. “Anyone can throw a different transmission in and go faster, but everyone has already done that,” Mark told us. “I hit my 8-second goal on what wasn’t even a good pass (the converter was unlocked). In the future, I want a 7.99 pass on the Allison in the quarter, and a 4.99 in the eighth-mile.

If you don’t think getting the commercial-grade Allison to shift fast or staging on the foot brake isn’t enough of a challenge, think about this: Mark is campaigning a Duramax with a single CP3, Fingers’ oval bowl cast-aluminum pistons, and a factory LLY ECM. While the Carrillo rods and SoCal Stage 2 heads say it’s a built engine, it’s original intent certainly wasn’t to be pushed into the 7’s in the quarter-mile. Look for Mark to hit his goals at the end of this racing season or early in 2021.