Slant 6 Exhaust Manifold Washers

See section 11 page 1 and 2 manifold replacement. The 1970 Hamtramck Registry "1972 Dodge TSBs" Page
I go along with all that, but I would use extreme caution about the information on page #2. The two outboard retaining bolts are only 5/16 and they are pretty long. I would advise against going up to 20 LBFT. That's a lot of torque for a 5/16 bolt. I don't think I'd go any more than about 15. That's all I tightened mine to two years ago and they've gone nowhere yet.