Exclusive to Allpar. Prefix Arrow Racing (PAC) has developed a new crate engine for Mopar enthusiasts to install in classic or modern muscle cars.

Prefix Arrow 392 Hemi crate engine

The engine uses the Mopar 6.4 liter (392 cubic inch) cast-iron block, with the aluminum 392 “Apache” cylinder heads (valves are 2.140” and 1.650”).  Some of the specifications and included items are:
  • Forged internals: 6.200” H-beam 4340 rods, 4.090” Mahle 4032  pistons, and a Mopar 3.720” stroke crank
  • Comp Cams custom street camshaft with or without VVT (customer option). Total valve lift in the 0.630” range with PAC Racing valve springs and Trend Performance pushrods.
  • Mopar factory-engineered rocker arms and lifters, with Prefix Arrow-modified extra oiling to the rocker arms and valve springs.
  • Mopar rear sump 7.5” deep oil pan with factory pickup
  • Custom oil dipstick (to clear either exhaust manifolds or headers)
  • Prefix Arrow single-plane EFI aluminum intake manifold with custom fuel rails and brackets.
  • Holley four hole (1.750”) throttle body, with a ½” four-hole spacer
  • Prefix Arrow aluminum valve covers with a black wrinkle finish, covers are designed taller than stock so custom valve train/rockers can be installed if desired.
  • Engine will come with a Holley Hemi engine harness with all factory Hemi sensors (One NTK O2 sensor included). Also, Mopar factory 6.4L/392 ignition coils included.
  • Engine will use Mopar 6.4L/392 accessory drive setup with a factory 220 amp alternator, factory A/C compressor and a KRC power steering pump with integral reservoir (6 inch aluminum diameter pulley on pump).
  • Mopar 6.4L/392 heater hose tubes installed on engine. Factory thermostat and housing will be included.
392 Hemi crate engine

The Prefix Arrow Racing crate engines come with either a Holley standalone fuel injection system (for use in classic muscle cars) or a Mopar stock GPEC engine controller with an SCT X4 programmer (for modern muscle cars).  Engines will come ready to install, with all  calibrations for the customer’s chosen system.

The new Prefix Arrow 392 crate engine will have around 500 pound-feet of torque and 580 horsepower (depending on VVT option) on tap, with the ability to adapt the common mechanical kickdown found on a 727 Torqueflite.

crate 392 Hemi

But that’s not all… Prefix Arrow Racing will soon debut an aluminum 426 Gen III Hemi crate engine, with options for a front-driven distributor, fuel injection, or a carburetor, and a mechanical fuel pump.  The 392 engine will also get these options at a later date.

Pricing for these crate engines is being finalized, with the goal of keeping the engine as affordable as possible without sacrificing quality and durability.  Contact Prefix Arrow Racing at  248-852-5151  to purchase one of these crate engines.

Prefix Arrow Racing recently launched new spec engines for Canadian NASCAR entries as well, which were covered first at Allpar.