You'll have to decide how far down the rabbit hole you wanna go.  Maybe start with a horsepower or performance goal and aim for that.  An Edelbrock headed 390 can make 400 hp pretty easily. 

I find it really troubling that some guys think that they are entitled to the intellectual property of others. 

Person 1:  "I've been at the dyno all day long.  I've spent $1000 on cams and spent an 8 hour day there swapping cams out." 

Person 2:  "Give me your information or I'll throw a tantrum and threaten to leave the forum."

Some confusion. You sold this customer an engine/cam that does not work well
with their transmission gearing and it's the customers fault?

But let's think of options here on what could have happened:

1.  Car was finished way after the engine was finished and the goals changed as the car progressed.
2.  Had originally planned on a C4, but the engine made so much power that the customer decided on a PG.
3.  Customer thought he may like to spray to hit 1000 hp and then decided he wanted the high 1st gear ratio to help with that.

A Clevor is a Windsor block with Cleveland heads. 

I will tell you that Clevelands/Windsors/Clevors can make lots and lots and lots of power.   That 777 hp 434ci Clevor is not out of the ordinary. 

But I will also tell you the Clevelands/Windsors/Clevors don't have near the pedigree of a Ford FE.  Nor the nostalgia.  Nor the looks. 

Performance Summary:
      Cubic Inches:    465           Dyno brand: Stuska
      Power Adder:    Nope     Where dynoed:  Dale Meers Racing Engines
      Peak Horsepower:  575 @ 6000
      Peak Torque:  545 lb-ft


Engine Specifications:
   Block brand, material, finished bore size, other notes:  Factory Ford 427 S/O, hydraulic block
     
   Crankshaft brand, cast or forged, stroke, journal size:  Scat 9000 series 4.125" stroke
     
   Connecting Rods brand, material, center to center distance, end sizes, bolts:  Scat I-beam, 6.700

   Piston brand, material (caster, hypereutectic or forged), dish/dome volume, static CR:  Custom Racetec, dish, 9.8:1

   Main Bearings, Rod Bearings, Cam Bearings brand and size:  Federal Mogul 125M, Clevite CB743

   Piston rings brand, size, other notes:  Total Seal, 1.5/1.5/3mm

   Oil Pump, pickup, and drive:  Melling M57B

   Oil pan, windage tray, oil filter adapter:  Canton deep front sump, factory style oil filter adapter

   Camshaft brand, type (hyd/solid, flat tappet or roller), lift and duration (adv and @.050"):  Custom Lykins Motorsports hydraulic roller

   Lifters brand, type:  Morel

   Timing chain and timing cover:  Factory timing cover, Cloyes billet

   Cylinder heads brand, material, port and chamber information:  Factory Tunnel Port, no port work

   Cylinder head flow in cfm at inches of lift (28" H2O pressure drop):
      Intake               Exhaust
      .100               .100
      .200               .200
      .300               .300
      .400               .400
      .500               .500
      .600               .600
      .700               .700
      .800               .800

   Flow bench used, location:

   Intake valve brand, head size, stem size:  SI stainless, 11/32", 2.250"

   Exhaust valve brand, head size, stem size:  SI stainless, 11/32", 1.750"
   
   Valve springs brand, part number, specs: 

   Retainers and locks brand, part number, specs:

   Rocker arm brand, type (adjustable or non-adj), material, ratio: T&D street, TP, 1.75

   Rocker shafts and stands, brand, material: 

   Pushrods brand, type, length: Trend, 5/16", .105"

   Valve covers, brand, type:  Blue Thunder/Holman Moody

   Distributor brand, advance curve information:  Factory FE, Pertronix, locked out

   Harmonic balancer brand:  Powerbond

   Water pump brand, type (mechanical or electric):  Factory style replacement

   Intake manifold brand, material, porting information:  Factory TP, 2x4 single plane

   Carburetor(s) brand, type:  Holley 710's, Drew Pojedinec

   Exhaust manifolds or headers brand, type:  Dyno headers

From what I understand, Ross asked Jay if it was ok....

If not, I'll take it down.  No biggie.

Most of the engine builders on here can get whatever Jegs/Summit can get, and probably for the same price.