It only requires a very small coolant leak into a cylinder for the steam from the coolant to keep the chamber clean. If the head gasket blows between cylinders 5 and 6, then coolant will leak into both cylinders. Once you get the heads off, by looking at the gaskets, combustion chambers and the face of the pistons, it will be very obvious which cylinders had water leaking into them and which didn't.
When installing the intake manifold, you only want to torque the bolts down once. This is normally enough to keep the water ports from leaking. Again, use the OEM graphite gaskets for this. All of the aftermarket paper gaskets for this job are junk.
When you take the heads to the machine shop, they will disassemble them, check the guides for wear and check the heads for cracks. If the guides don't have much wear (very little valve wiggle), then they could grind the face of the valves and the seats if needed. If the guides are worn much, then they need to replace them before grinding the valves and seats. Obviously replace the valve seals. I would avoid Teflon here. They always seem to fall off. Use Viton rubber if you can find them.
If they do grind the valves, you may end up having to shim the rocker arms to get the lifter preload back to spec. This will depend on how much material they grind on the seats, valve faces and valve tips. Before they disassemble the heads, have them measure the valve tip height on all cylinders. Then measure the same dimension after all machining is done. That way, when you install the heads, you will know which cylinders need its rocker arms shimmed and by how much.
https://www.summitracing.com/parts/fms-m-6529-a302/
Connect With Us