I have recently purchased an engine degreaser for my engine rebuild.
After i wash the block and head with it, it turned to somekind of dark grey in color, rinse with few shots of WD-40.. The dark grey color is still there... will it be ok if i just left it be and continue with my engine building... or do i need to clean the dark grey spots out... the spots already covered almost 90% of my block and head... please help me out guys..

 

Pics might help. What degreaser did you use? Undiluted simplegreen or purple power both work really well. You could try scrubbing with a different degreaser and a bristle brush.

 

Will post it later once i get my camera phone to work. Its says there, alkaline degreaser and the degreaser is blue in color.. will it be ok if i just leave it like that... cause i didnt see any white spots like alu corossion or anything...its just discolor thats all... .
Already use brake cleaner... but the stains wont go aways... its like the dark grey color is attach to the alu.. so im using steel wool brush, it removes that dark grey thingy... but im not intended to use the steel wool brush on the main journal bearing surface.... can i just leave it like that.. will it do any harm to my block if i just leave it like that?