Intake and exhaust manifold
Intakes are just cast iron, will never die. Aluminum ones get nasty cracks in the plenum floor and have porosity issues. Clean and paint iron ones, good as new. Exhaust can and will crack if not mounted correctly, they are being repopped with modern ribbed design for about 150. Here is an early and a late EGR intake, The red one is the older one, just cleaned and painted....