[Scnell Gelb]

The only reason I cleaned the bores on my M96 was to inspect for fine cracks and to be able to accurately mark the many measuring points with a Sharpie.
I used acetone on a 'white' Scotch Brite pad for cleaning.Do not saturate the bore with acetone! You want to remove any loose carbon and 'dirt' but leave the alloy 'saturated' with oil.
I suggest you research the whole bore/taper measuring issue.
It requires special tools, pains-taking calibration of the tools,practice using them, multiple ,replicated measurements, charts of measurements. It takes hours to do correctly.
You will be measuring to +/- 1/10 of 1 thou. That is very difficult to be both accurate and consistent. It is so picky that you have to make sure you do it at a stable ambient/crankcase temperature. Even the temperature of the measuring tools is critical at that degree of accuracy. Yes, it is extremely tedious and the tools are expensive !
I doubt many diy rebuilders do this and if they do ,the results may be inaccurate. I get the impression that many diy rebuilds are just slapped together and quickly sold. I plan to keep my car so I made my measurements on multiple occasions and got very frustrated trying to replicate the previous measurements exactly.
If the subject interests you, I suggest you start a separate thread on the bore taper/ovality issue .There are no Porsche specs that I know of so I resorted to guessing based on Jaguar specs.for their Nikasil (not alusil I know)engines Who knows if that will work !
Then inspect the plating on the piston skirts for wear(wear = need new?) and measure the crankshaft journals and all the camshaft bearing areas.
I could go on but just wanted to give you a clear impression that rebuilding an M96 is correctly way,way more complex (& expensive!!) than I had anticipated. So know what you are getting into before you spend much more ?
I wish Wayne or Jared Fenton would write a book on the M96 rebuild procedures.