Hughes Performance Street and Strip Transmissions 34-1HD

Hughes Performance builds the 34-1HD as the heavy-duty version of its Chevy-pattern 3-speed automatic, remanufactured and rated to 750 horsepower with an upgraded drum and sprag assembly backing a 2.48 first gear ratio. Power routes through a 30-spline input shaft, shifted by a forward-pattern valve body that still allows manual gear selection when wanted.

Where the extra duty comes from

The heavy-duty drum and sprag assembly is built to carry more torque through first gear before it slips or wears, which is the main difference between a 750-horsepower-rated case and a lower-rated one that otherwise shares the same bellhousing pattern and gear ratio. A deep steel pan in a chrome finish supports the added fluid volume that higher-power use calls for, and is sized to the deep style rather than a stock pan.

One part that is not included

A speedometer drive gear housing does not ship with this transmission, so keep your existing one or source a replacement separately if your speedometer connects through the tailshaft. A 4.000-inch tailshaft and slip-on yoke carry over from the rest of this Chevy-bellhousing family, so matching driveshaft hardware should already be close at hand.

Does it bolt to a standard Chevy-pattern bellhousing? Yes, this case uses a Chevy bellhousing bolt pattern, so check your existing bellhousing and crossmember against that pattern first.