From the Mopar Montana guys
https://www.moparmontana.com/tech-faq.html
HEAD TORQUE
Your block should ideally be decked to give a smooth flat surface for optimum sealing. Head bolt holes should be chamfered and thread chased with a tap after decking. A modern composition head gasket will give the best results and these are available off-the-shelf from Fel-Pro for 23" and 25" Mopar flathead 6's. Fel-Pro recommends using a sealant on the copper (block) side of the gasket. Vintage double sided copper gaskets require sealant on both sides. A copper spray such as Copper Coat works well. EDGY heads have a very smooth, flat surface for use with modern gaskets. Due to this, no sealant is required on the head side of the Fel-Pro gasket.
Any head fasteners that go into the coolant jacket (ALL of them do on Mopar flathead 6's!) should have a non-hardening PTFE sealant such as ARP or Permatex applied to the threads. Hardened and ground flat washers should be used, and need an ID chamfer if using bolts (chamfer goes up). ARP makes the best ones and are available directly from us. Ensure that the fasteners you are using fully engage the threads in the block. If using ARP studs, the upper threads, and nut/washer faces must be coated with ARP assembly lube.
Torquing should be done in three stages following the order on the attached picture. Use of a high quality torque wrench is highly recommended. Torque values for 23" and 25" Mopar flathead 6's are as follows:
First stage: 25 ft-lbs
Second stage: 45 ft-lbs
Third stage torque is fastener dependent:
Stock head bolts: 65-70 ft-lbs (with sealant on the threads, oil underhead and on washer faces)
Stock studs and nuts: 52-57 ft-lbs (sealant on block threads, oil on top threads and nut/washer faces)
ARP studs and nuts: 63 ft-lbs (sealant on block threads, ARP lube on top threads and nut/washer faces)
Run the engine to normal operating temperature and allow it to fully cool over-night before retorquing.
Repeat this procedure at least three times, or until there is no more appreciable take-up on the fasteners.