That engine is a pig, the plugs look terrible, I would expect 12 -15 mpg at a minimum.
As usual there are critical unknown factors
Operating temp?
Timing chain stretch
Valve seals?
Is the interior of the intake manifold wet with gas?
Quality of the spark plug wires
No the thread is not closed...the proper adjustment for drum brakes is not 10 clicks back after the shoes drag. The proper adjustment after making sure the wheel bearings are properly set is the shoes are lightly dragging.
there are great mopar performance books - the engine book - it will in detail give the information required regarding the 440 cast vs forged crank.
As far as a pilot bushing vs the roller bearing the roller bearing is far superior to the bushing - period. the pilot bushing is old school and...
Microfiche reader makes parts number chasing thru the model years easy, I had a compete system at one time.
Frank originally was in the old mopar car repair business - fixing the numerous old mopars still on the road. In the process he discovered a large demand for the parts for these cars so...
Frank M had some questionable customer service practices. That aside he was the smartest Chrysler parts person. Frank had a complete collection of parts manuals and all the associated documents like a complete trail of the supercession list for parts. With these docs one could chase a pn thru...
Back then seat belts were an accessory....look in the accessory catalog and accessory section of the parts manual for 64-5-6-7. There are both catalogs and parts listing for accessories in mopar parts. Once there is pn I would also check the superseded [ss] list catalog. Every model year...
Please stay on subject, this conversation has nothing the do with the parts man.
As for the problem with the rotors...most likely those are offshore rotors and the tolerance for the od of the hub is too large.
In hindsight all the mating parts should have been checked for assembly before...