Not for nothing there are way better stock appearing heads out there. I can appreciate the stock build as well though. I have bone stock numbers matching cars and resto-mods.. stock appearing builds with extra HP are my favorites..
The duramax and allison made the swap much harder I think. The motor and trans are both huge, plus the intercooler and giant radiator. I have a thread here from awhile back. I'll post the link if i can find it.
People think I'm nuts for this but a solid source for real GM parts is the boneyard. I have pulled modules from parts cars and gotten a long life from them.
Watching the first vid the choke appears to be working close to correct. It doesn't sound like the fast idle cam engaged though. It should be running around 1100 rpm. Sounds like its puttering at a normal idle.
Also didn't see a waterfall fuel leak.