What is the sequence and the torque of the D3400 starting engine headbolts.

Hi NVC,
here are the spec. torques for all ponies and EDB's sequence that I was taught at The Dealer.
The final torque was to be reached in 3 steps--1st step 15lb/ft, 2nd 25lb/ft and 3rd 35lb/ft for your engine.
I also like to do each step by going over each step multiple times until no more fastener movement occurs then move up to the next step.
The final torque should be recheched after 2 or 3 starts and again after another say 10 as the old copper asbestos head gaskets tend to shrink away under the head after a few heat cycles and so need retorqueing several times.
Hope this helps.
Cheers,
Eddie B.

Thank you Eddie B for that good info.