This is for Marv.  I’m having trouble with the private messaging so I’m posting the answer to your question here.

 

By the book and for aluminum heads, 8-12 lbs/ft torque for spark plug tightening.    Be sure to use anti-seize on the threads.

Lorena, Texas (South of Waco)

Watch using "Never-Sieze" on plugs. Too much will turn to carbon and you will remove the threads along with the plug.

Frank/Rebop

Bristol, In ( by Elkhart) 

Don't intend to hi-jack this thread but what is the best plug for a y-block, 292 heavy duty truck engine with a 2-4 set up and it is not burning all the gas, plugs are black. Right now have a set of AC in it.

Terry

Terry.  I’m assuming you posted this in the aluminum head section because you have aluminum heads.  If so, then the Autolite 3924’s would be a good start.  If you have iron heads (18mm tapered seat), then the Autolite 46’s would be a good starting point on a low compression engine.  If your AC plugs cross-over to the same number as either of these, then you potentially have too rich a fuel mixture at idle and/or at low speed which will be difficult to correct even with hotter spark plugs.  If you continue to have issues around this, feel free to start a new post in the technical section where it will get more traffic and also be more specific to your problem.

Lorena, Texas (South of Waco)