take the plugs you have now and clean up nice one by one with your wife's tooth brush and gas blow dry and re use. (don't use your own tooth brush)
Do again if you foul them again get the ignition right and they will clean up themselves.

Think key on through the ballast is 9/9.5 volts.
Check the in and out sides of the ballast for voltage too.
There may be big resistance or poor connection coming through the fire wall

When you put your msd in you bypass ballast.

Hydraulic lifters need proper setting or they rattle without enough preload (or can hold valves open with too much) loose and noisy is better IMHO.

Cam can be degreed in car not near as nice as doing it on assembly why in this day an age a engine builder would not do cam degree he should have been insisting it be checked takes 15 minutes to check before heads and timing cover go on???
bet he builds a lot of slow motors!

Brand new Chinese balancers can have the keyway off by a lot kids over there don't know or care! But we get cheap chit