5 miles?  Are you sure it is the rear main seal and not something else like an oil gallery plug or the rear camshaft plug being installed backwards?

The silence is not encouraging.    Reading previous posts regarding rod bearings it sounds like ACL and King are other good options.  I'll take any input regarding rod bearings that are on par with the speed pro bearings that are not available.

I take it 3D printing is not a viable option for making the parts?  I'm aware that some very intricate parts like the one in this video can be made, but I have no knowledge of the costs involved.

So I did a small amount of searching.  Appears to be well beyond EXTREMELY cost prohibitive.  I'm still trying to wrap my head around how manufacturing facilities are justifying something like this (probably still too small for some of Jay's parts) versus having a part cast at a foundry.  Both options require final machining.

This is the type of thing that makes baby kittens cry.  :'(

Do you have anything "in stock" at all.  Smaller things like timing covers, etc. or is it everything (cast items) that needs to have an order by the 24th?

Nevermind.  I just read the post in the Vendor Classifieds. 

I was just about to pull the trigger.  Then I saw the cork valve cover gaskets.   

I do not follow many forums so it seemed prudent to ask.  As noted in the subject, I have a complete drivetrain (engine, transmission, rear axle) from a '66 galaxie.  I haven't gathered all casting numbers and such (it's cold outside right now), but to my knowledge they are all matching numbers wise.  I won't have a need for it but it seems like something that should be offered as a package for anyone looking for period correct or numbers matching drivetrain.  I am running with the assumption that the private classifieds on this forum would not have much interest in something like this.  If I am wrong in that assumption, please let me know.  If there are forums or other options better suited for making such an offering, please let me know.     Thank you in advance for any information.  I forgot to mention that the drivetrain consists of a 390 4bbl, 4 speed toploader and the 9" rear is 3.50 gears and has the vibration damper (whatever that was called) on the rear of the driveshaft.

No need for forgiveness.    For me, this thread is mostly about information gathering.  For example, prior to this thread, I was not aware that some 428 blocks cast in late '66/early '67 were cast with the bosses extra material in the web.

My 2 cents on the different block castings in relation to installing cross bolt caps in a nutshell.  While it isn't required (as you have noted) to have a block with the cross bolt bosses to install the caps and benefit from them, for whatever reason those blocks were cast with the bosses and extra material (crows feet) in the webs.  While not necessary by any means, it seems like a better base/foundation to start with if cross bolt caps are being added.  This, of course, assumes availability.  Sometimes you have no choice but to work with what is available.