Intake to head torque value in the Buick manual is
32 ft#. I bet the ATR line is for an 86/87 and won't fit, but
you can call and see. Spark plugs? Well, that's like
Chevy's - everone has an opinion. I use Champions
gapped at .035", seem to work OK for me, but I'm
no racer. So that may not be valid for everybody,
or you either. The fail safe is to go with the manual,
of course (.040", I think). Reseaarch the GNType.org,
and this board and there will be reams on this subject.
On torquing the intake, start in the center and do an
alternating pattern across each side of the intake.
Snug it down, then go back and torque to final
value, same way.