I might be wrong - won't know until you try - but on your build I bet the change to a single plane gets you close to nothing...

     Remember, the O.P. was an inquiry of single-plane intakes and balance of flow values. This perhaps more of a theoretical concern, rather than an inquiry as to which design element actually would provide better realized performance.

     I do not disagree with your statements of the value of the dual-plane, and yes with the fuel being presented early in the gas column (carburetor or T.B.I.) often much of the resultant evidence of deviation in the air/fuel mix delivery is masked; but consider that invariably with the complications in port runner configuration of the dual-plane, particularly as the density and velocity of this gas column is increased, the dual-plane is more likely to falter in values of an equal or balanced delivery of atmosphere, and fuel, as compared to the single-plane arrangement.   

     Also, with the use of T.B.I. one is effectively negating the difficulties often encountered with the 360° vs 180° plenum intakes, with the effective drafting of fuel from the carburetor; this perhaps also a consideration in the determination of selection.   

     Scott.

I hear you Steve, but it would require a transmission change to fit the Bell housing bolt pattern on the MEL..  How about a 57 Custom 300?

     I believe there are three different bell housing bolt patterns for the MEL family of engines, and with the cubic inch capacity, I would assume the they started with the later 462 engine which used a modified bell housing pattern C6 transmission, a bolt pattern which surprisingly (was required for '68 (1/2?) Lincolns) is also present on the 385 series engines.     

     Also two different block/motor-mount patterns within the decade of production.     

     Scott.

If I have him turn it to the lowest spot it is going to be a vestigial oil slinger (in other words quite small) and I'm not sure if that is going to cause me any issues or not...

    No problem, as the slingers' intended propose was engineered in the time of the "rope" seal era.     

In other words small and round or somewhat larger and egg shaped.?.... Which is preferable...?

     I would prefer to prior, particularly as the machining effort to the block, producing a professional and accurate result would be more difficult.     

Bonus points if you can tell me how they get like that, seems like it would take real work to machine it elliptical... <shrug>

      No, it's just Chinese    
   
      I imagine that the seal diameter may not be elliptical, but perhaps just machined off center from the main journals, as this surface is machined earlier in the roughing process, and apparently the crankshaft is re-fixtured for the cutting/grinding of the mains, and not replicating the previous effort.         


     Scott.

     At the, as we always knew it as, "Turkey-Rod-Run" in Daytona last weekend (they call it something else now),...........drum roll please!........... how about an aluminum intake manifold for the Studebaker 299/304.5 cu. in. "R3" supercharged engine!  And the vendor stated that after an exhaustive search he had not been successful in determining what it fit, ............but I know!       

     Now you won't find one of these everyday, as Andy Granatelli who had purchased Paxton from McCulloch and then Studebaker bought them, but didn't survive long after, so few "R3" engines were ever installed in any cars (perhaps something like nine Avantis and couple of Larks is the count) and post Studebaker involvement, there was an undetermined number of engines and parts sold off by Granatelli, but perhaps something around one hundred plus or minus total in different states of completeness.

     So now, for my 289 (no, not A Ford 289!) all I need is the "R3"/"R4" exhaust manifolds; the search continues!     
   
     BTW, the Studebaker Avanti "R3" was "officially" the fastest (170+ M.P.H.) American production car at the time!     

     O.K, since this is the FE Forum, not as rare, but I did pickup a '64 410 block, the one with the extra web and cross-bolt bosses, std. bore, nice shape, destined for some high- revving 390 or something project w/ cross-bolt caps installed.  And, a 9 inch "N" case w/ "Daytona" support too.   

     Scott.

...............................and pinning the distributor at max timing.

............................... - but I do occasionally hear it kick back during cranking.

My question is, what is the benefit of running the engine at total (i.e. max) timing all the time except on start up?

     Having the distributor timing advance function "locked-out" is fine for engines that when in use remain at an R.P.M. that would/should be experiencing full advance anyway; as if only this reduces the possibility of experiencing component or function  failure of such system in competition.   But in the more dynamic R.P.M. operating range required in most "street" operation if this is practiced, one may experience greater difficulties in the starter motor operation (if not retarded as you mentioned), and particularly in manual transmission applications in the transitional throttle applications implemented during shifting and at lower to mid range R.P.M's at moderate to heavy loads experience detonation ("engine knock") which is best avoided.       

     Scott.

I get the velocity part, it is our friend. ..................... There has to be some middle ground between port size and velocity? ( I'm asking, not telling).
Thanks,
JB

     Just remember: generally to gain in velocity, one much increase the resistance to freedom of flow.       

     And, in answer to the question:  yes!  And this is a trade off that must be established for best effect for each instance; hence why no one engine build combination works best in all instances.       

     Scott.

     Unfortunately, this clearance relief weakens this casting area supporting the pilot bearing, although under the vehicle acceleration load the force is greatest in the direction of the support web, this area is particularly vulnerable to failure if the pinion bearing preload is not maintained, thereby allowing excessive movement of the pinion head and transfers excessive responsibility to the pinion pilot bearing, and I have witnessed failures.       

     Therefore, back when all we had were O.E.M. gear sets and cases available, to reduce this intrusion and otherwise sum of material removal from the casting required, I would chuck the ring gear in the lathe, spun at a good speed, and applied an air powered disc sander, with the 60-grit, 5-inch flex-disc, at a high speed, and remove the required sum of material from the gear profile.  This execution, with reasonable technique was surprisingly quick an presented a good appearance. And for the naysayer, this reduction in the profile was practiced later by the aftermarket gear producers, this being a surface of little consequence in the gear set relationship anyway.       

     Scott.   

     In the original applications from the O.E. the cases had an additional "clearance" machine operation for the numerically higher gear set (perhaps starting at 3.89/3.91 : 1 (?) and up) intentions, executed on the loop cast to retain the pinion pilot bearing (R1535TAV), as the inside "toe" of the ring gear intruded.

     The later aftermarket gear sets had a reduction in this area of the ring gears' profile to permit their installation with a reduction of difficulty.         

     Scott.