Barrel tuning info required

I need info on tuning the malossi 136. With the exception of enlaring the cylinder base transfers , I would appreciate any info on exhaust port alterations etc; as in „the port must be raised no more than 1mm“

the link below doesn’t really provide and specific info that i could decifer.

http://216.239.39.104/translate_c?hl=en&u=http://people.freenet.de/landrover/seite1.htm&prev=/search%3Fq%3D2strokerz%26hl%3Den%26lr%3D

or maybe you know someone, who can pass their experience of malossi barrel tuning expertise on to me