What do you mean clean up the 7M? Basically what happened was that the HG had a catastrophic failure. The block was corroded in areas and therefore had to be removed to be decked.
When the engine was out it received new pistons, bearings, cylinder hone, head was machined... blah blah blah. All done professionally.
Unfortunately due to a lack of JZX81 halfcuts in Australia these days I didn't go the 1JZ. I think they are a bit hard to find these days.