Hi Tony;

You are right; arrows should point towards front of engine.

Letters "A" to "F" indicates the tolerance class of each cylinder and piston. At the factory, and after drilling up the bore in the block the exact diameter was measured and then labelled. Same with the pistons; they were classed accordingly so that an "A" cylinder always got an "A" piston etc.

You can not change the cylinder of a B16, as they are drilled into one lump of swedish steel (not rechangeable liners, as in some other engines). You can either 1) do nothing 2) hone them if wear is limited (usual case) or 3) have them rebored to an overdimension, in such case you will need new pistons and rings. You can only decide this after carefully measuring each cylinders ovality and wear, unless you have apparent damage after e.g overheating or lack of oil.

If the engine was running well before to lifted off the top and did not produce blue smoke (burn oil), you could/should only limit your intervention to clean out the soot from the piston tops. It is normally more important to have the top (valves and seats) serviced, which you can either do yourself or have a workshop to do.

I highly recommend the Volvo service manual if you aint got it already, it's available here & there in reprints or on a handy CD rom from Scandcar in the Netherlands (searc the net and you'll find). They are quite detailed and explains carefully what/when to do certain things and what to observe.

Good luck!

Ola.