Porting a ko3 exhaust manifold

[dilbert]

wont the head need matching to the exhaust ports ?

[brianpologti]

Iam  running a ina one which I ve heard some crack , some don't, but I ve picked up a spare manifold so   I thought I get it ported , as ive got to have the head off , slight oil leak and don't want to find it and get stuck. But then I ve heard standard ones crack too , as my daliy did at 130000 so luck of the draw ,