...............................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.

     

       The statement made previously, that the damper unit on the FE 428 is of neutral imbalance sum is correct, and if the shop performed the balancing effort executed such properly, then so it remained, with only perhaps the corrections required to establish such in a more accurate value.  The problem is, you will have to establish this, as if any "corrections" have been made to the damper, lazy balancing executions will at times utilize, improperly, this available surface to permit finishing the job with greater expediency.     

     Scott.