632 BB Chevy with 850HP

Starting at Call For Pricing

When you are building or looking at re-powering your airboat low to mid range torque is what you want. Running on dry ground takes a lot of torque and power to make it happen (We have done just that). We here at Proformance Unlimited have tested many different engine combinations perfecting the perfect balance of torque and power to allow you to get the most out of your airboating experience. Designing this type of extreme duty engine goes well past just making good power and torque. We have developed several combinations that are extremely durable and will allow the user to enjoy his or her air boating experience with limited down time and maintenance.





  • Fully machined Dart Big M tall deck 4 bolt main block
  • Block painted with 3 coats of high temp ceramic engine paint
  • Forged steel crankshaft 4.750 stroke
  • H-Beam connecting rods with ARP bolts¬†¬†
  • High performance pistons (SRP, JE, or Mahle)
  • Performance rod and main bearing (Clevite)
  • Performance rings hand filed to match application
  • Rotating assembly is balanced
  • Custom ground hydraulic roller camshaft
  • Roller lifters
  • Three piece double roller timing set
  • AFR CNC ported performance aluminum cylinder heads
  • Screw in studs and hardened guide plates
  • Manley chrome moly push rods
  • Performance roller rockers
  • Melling high volume oil pump and screen
  • 8 Qt. stroker oil pan
  • Dipstick and tube
  • Timing cover
  • Performance balancer
  • Fel-Pro performance gaskets
  • Edelbrock TD Victor intake manifold
  • Chrome thermostat housing
  • Quick Fuel 1050 cfm marine carburetor
  • MSD marine ready-to-run distributor
  • Autolite spark plugs
  • Taylor 8mm Ignition Wires (Color Of Choice Black, Red, Blue, Yellow, Green, Orange No Extra Charge)
  • Water pump
  • Aluminum valve covers
  • Chrome breather
  • Engines are photo documented during the building process
  • Each engine is dyno tested, timing set and carburetor adjusted for optimum performance
  • We video tape your engine and send you a copy
  • 2 Year 250 Hour Marine Warranty

Does this engine look like a good fit?