Honing plate question

I can measure the distortion with a dial bore gage. Technically if the plate is not on, the bores should be slightly out of round at the top 1 1/2". That's where the rings are working the hardest. It's worth measurable power, which is why I bought my own plates. You don't need the opposite bank, but you do need the mains torqued. If you don;t have a plate, you can also use flat ground washers, stacked up to about 3/4" thick on each head bolt. Andy F. did an experiment with that and it was the same affect as a torque plate.