After switching over to an Iwasaki bulb a few days ago,I planned on switching out my M58/H37 ballast to a H37 ballast(H37 is the preffered Iwasaki ballast).
After talking with Dakar,he recommended just switching the capacitors out.
The M58/H37 uses a 15uF cap while the H37 uses a 22.5uF cap.The results are in the pics.
This is a before pic taken without actinics
And a really bad after pic(microbubbles,forgot to fill up the top-off bucket)