Use no sealers here but put anti seize on your studs, tighten properly. This is
also a great time to work the intake port on # 3 . It is almost always 2mm off set.
The factory was perfect on 1,2,4. but the jigs were off on 3. At least I have never seen
one that was good.(in the last 50yrs)
I use the al. foil method, to make a perfect template on the cylinder head.When transfered to the
manifold the problem is clear and easy to fix(drimill). FYI . Probably a coinkingdink but it seems
to be #3 that is the cylinder to fail when a motor blows up.
Mad dog