Two things. I should have pointed out that I only use 1 rod and piston as mentioned above. If you are using stock rods, you really need to measure them. You have no idea how many times they've been rebuilt and that can change the length.
Aftermarket rods are usually dead nuts on. Good Pistons are too.
I also want to mention gasket surface. Back in 1995, I went to a seminar put on by Fel Pro or whoever owned them at the time.
The biggest take away from that was surface finish. The upshot is, regardless of block or head materiel or gasket material, you want a very fine finish. Rough surface finish went away a long time ago. The lie about giving the surface "TEETH" to grab the gasket was wrong.
In fact, if you've ever seen a block or heads come in that went out with a rough surface, the first thing you notice is how much smoother the finish is after run time.
This is because the gaskets main job is to follow the head up and maintain seal on the combustion stroke. It does not matter how many bolts are around the cylinder, how big they are, or even if they are studs.
Every firing cycle lifts the head off the block. And the gasket needs to be able to follow that separation and keep a seal. A rough finish does nothing to help that.
What actually occurs is that during start up and cool down (and even in operation as load changes occur) the head and block are growing and shrinking in all directions. That rough finish is actually worn down by this movement. In fact, as this wear occurs, it not only smooths the head and block surface, it removes materiel from the gasket itself.
And, this causes the the fasteners to lose tension. Now, you start seeing head gasket failures. I can't count how many engines I've disassembled that had head bolts that were loose. And failed gaskets. You get it apart and you see a rough surface that it now relatively smooth.
Gasket surfaces should be smooth with out burnishing.
