Established in 1991 by John Hennessey,[2] their main facility is located 45 minutes west of Houston in Sealy, Texas.

Besides performance automobiles, they also tune pickup trucks and sport utility vehicles such as the Ford Raptor,[4] the Ram TRX,[5] the Jeep Grand Cherokee,[6] and the Cadillac Escalade.

Upgrades included a US$37,000 engine upgrade that utilised enlarged cylinder bores, and longer stroke to increase displacement from the stock 488 cu in (8.0 L) to 514 cu in (8.4 L) along with forged steel connecting rods (titanium rods were an extra $3,500) and forged aluminum pistons; the whole assembly was then balanced and blueprinted to bring the total power output to 650 hp (659 PS; 485 kW) at 5,800 rpm and 650 lb⋅ft (881 N⋅m) of torque at 4,500 rpm bumping the compression ratio up to 10.5:1.

New engine management software increased the idle to 1,000 rpm, disabled the 1-4 skip-shift transmission feature, turned the cooling fans on sooner, and packed recalibrated fuel and ignition curves.

Completing the package was the VenomAero carbon fiber body upgrade that reduced weight, added functional brake cooling ducts along with a rear wing and optimized downforce.

Three "World's Fastest Edition" Venom GT coupés were produced in 2014 to commemorate the car's speed record run.

[11] A roadster variant dubbed the Venom GT Spyder was launched in 2012 on the request of Aerosmith lead singer Steven Tyler.

The final edition gained a total of 204 hp (207 PS; 152 kW) and was 9 lb (4 kg) lighter than the regular Spyder.

In 2018 the Hennessey Ford VelociRaptor 6×6 option was made available, with a 30-inch extended frame and extra axle for a total of six driven wheels.

The package includes a high-flow supercharger and intercooler providing 14 psi of boost pressure, custom camshaft, ported cylinder heads, upgraded valvetrain with new springs, lifters, pushrods and valves and long-tube stainless steel exhaust headers with high-flow catalytic converters.

The optional road race pack includes a set of 20 inch light weight Hennessey wheels with Michelin Pilot Sport Cup 2 tires at the cost of US$6,995.