Seems like every Scat 331/347 combo I do has really tight rod side clearances when I measure during mock-up.  I think a lot of the combinations that utilize a factory FE crank with Scat H-beam rods do as well.  I always have the rods surface ground on one side to open the clearances up. 

As Barry shows, may not be necessary, but we get into the habit of going back to "what works" from past experiences. 

Pair.  Throw both rods on the throw, spread 'em apart and shove a feeler gauge in between.

Everything is GZ.  One of the best setups out there, IMO.  Comes with crank mandrel, mounting brackets, all hardware.  It would have come with the fittings and hoses, but I wanted to make my own hoses to match the engine.  Even comes with a little puke tank.

Performance Summary:
      Cubic Inches:   511            Dyno brand:  Stuska
      Power Adder:               Where dynoed:   Dale Meers Racing Engines
      Peak Horsepower:  723 @ 7000
      Peak Torque:  657 @ 4500

Horsepower and Torque Curves:


Engine Specifications:
   Block brand, material, finished bore size, other notes:  Pond cast iron, 4.375"
     
   Crankshaft brand, cast or forged, stroke, journal size:  Scat steel, 4.250" stroke, 2.200" rod journal
     
   Connecting Rods brand, material, center to center distance, end sizes, bolts:  Lunati H-beam, 6.800", ARP 2000

   Piston brand, material (caster, hypereutectic or forged), dish/dome volume, static CR:  Racetec, 2618, coated, 11.8:1

   Main Bearings, Rod Bearings, Cam Bearings brand and size:  Federal Mogul, Federal Mogul, Durabond HP

   Piston rings brand, size, other notes:  Total Seal, .043/.043/3mm, low tension for vac pump

   Oil Pump, pickup, and drive:  Melling HV, Moroso pickup, ARP drive

   Oil pan, windage tray, oil filter adapter:  Moroso road race T-sump, no tray, POP billet adapter

   Camshaft brand, type (hyd/solid, flat tappet or roller), lift and duration (adv and @.050"):  Custom Comp Cams solid flat tappet, nitrided, 270/280 @ .050", 108 LSA, 108 ICL, .650/.650 gross lift

   Lifters brand, type:  Crower Coolface SBF EDM

   Timing chain and timing cover:  Ford Racing/factory

   Cylinder heads brand, material, port and chamber information:  Custom ported Ford Tunnel Port

   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:  Ferrea hollow stem, 2.250"

   Exhaust valve brand, head size, stem size:  Ferrea 1.76
   
   Valve springs brand, part number, specs:  PAC 1255X, beehive

   Retainers and locks brand, part number, specs:  PAC titanium

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

   Rocker shafts and stands, brand, material:

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

   Valve covers, brand, type:  Holman Moody

   Distributor brand, advance curve information:  MSD, all in by 2500
 
   Harmonic balancer brand:  Powerbond SS

   Water pump brand, type (mechanical or electric):  CSR

   Intake manifold brand, material, porting information:  Factory Tunnel Port

   Carburetor(s) brand, type:  (2) QFT 725cfm carbs

   Exhaust manifolds or headers brand, type:  Dyno headers, 2" tube

Aftermarket block or factory block?  What kind of racing?

I've used a little of everything.  The FM bearings are nice and will drop right in.  If you have an aftermarket block that uses a Cleveland bearing, and you use something like a Clevite, ACL, or King, you will most likely have to cut the thrust bearing flange down. 

I use a lot of FM bearings, but I also build engines where I use coated bearings and usually reach for the Clevite HK series stuff.

Yep, ridiculously high.  Need to find someone else, or take Barry or myself up on using a broker.

You probably won't notice much difference.  If the current valves are in good shape, I wouldn't bother.  If you need to replace the valves and need a valve job anyway, probably wouldn't hurt anything.

What will help the driveability and the health of the motor the most would be to get a thinner gasket or have the decks cut.  Having over .060" of quench distance is not conducive to a happy engine.

Not sure about that one.  I normally remove the factory plugs and replace them with ones I buy from McMaster Carr.  They have a thread locking compound on them.