Old Pro Stock motors never die, they just work their way down to the sportsman classes.

Here’s a former Ford IHRA Pro Stock mountain motor built by Jon Kaase that later set records in NMRA and now resides in a Top Sporstman car running on the West Coast. It’s been detuned slightly from the days it was pulling over 1,800 horsepower on the Pro Stock circuit.

“It’s not an aggressive cam now,” says Kyle Curley, nephew and mechanic to Bob Curley, who campaigns in the engine in a ’57 Ford.

In the video above, the 816ci engine had just come from a freshening at Jim Spernak’s shop in Northern California and was being evaluated on John Beck’s dyno at Vintage Hot Rod Customs.

“We did some dyno pulls to figure the torque converter for the car,” Spernak tells EngineLabs, noting power numbers of around 1,500 horsepower with peak torque of 1,250 lb-ft. “I also cleaned up the linkages, belt drives and remounted the dry-sump pump.”

The engine was never a top contender in its Pro Stock days, but it also didn’t linger in the bottom of the field, according to John Hauf, who purchased it about a decade ago to run in the NMRA Pro 5.0 division with son Michael at the wheel.

“We actually picked up some power after we got it,” says Hauf, adding that he built a new intake manifold with shorter runners and made a cam change to run higher rpm. “It wasn’t a tempermental engine but it did require a lot of maintenance. We went through a lot of valve springs with that high-lift cam.”

The Hauf team won the championship 2006 and eventually set a record 6.56 at 212 mph, running a 2,550-pound car. Hauf says he took some cam and rocker ratio out of the engine before selling it to Curley in 2009. An oiling problem in an early run sent the engine to Beck.

“I got the cylinders round again and put a new crankshaft in,” remembers Beck.

Considering a new Kaase or Sonny Leonard mountain motor will cost in the neighborhood of $115,000 to $130,000, Curley probably got a great deal on his Pro Stock powerplant and can keep it for some time with the relaxed tune.

“Top Sportsman is just a fast bracket race,” adds Curley. “We don’t need to be killing valve springs every 15 runs.”