has the factory machined surface next to tensioner.Yes, it's better to run the higher idler, but not necessary.
Also, depending on the machine shop, turn around times vary greatly.
When i had my 30 done initially, was in and running in 2 months.
But, I had to dick around with exhaust and such(getting it towed here and there, etc).
Some machinists get backed up themselves and can take a couple of months.
The people I use have an approx turn around of 2 weeks on a bottom end.
Head work obviously takes different times.
But....
It could all be done(theoretically) at the same time.
As you said, a well equipped shop, that carries out these jobs for a living could do it in 1-2 months.
But as already mentioned, they overbook because they don't like saying no.
And once the engine is out, it's alot harder for you to just say that's it, and collect the car and go elsewhere.
It's a shame really.
I'd prefer to be told no, and given an alternative book in date further down the track, then keep getting stalled and impatient.
Anyway, hope it's coming along well.
Also hope mines ready by mid February, but doubt it due to crank and funds.