225 slant 6, exhaust manifold triangles

Welcome!
There is a procedure to follow when you bolt the intake and exhaust manifolds onto the head. Just cranking down on the nuts will lead to the exhaust manifold cracking. The center part is the only area that is stationary because of the conical washer. The triangular clamping washers allow the manifod to expand and contract. The hardware used is very specific and not every location uses a triangle. Brass washers are also used in a couple places. Try not to break off the studs which only lead to more work. The Remflex gasket is the best.

Think about getting the Doug Dutra book "Chrysler Slant Six Engines" Dr. Dodge knows his stuff.
ISBN 978-1-61325-432-5