0
Was hoping to keep with 25mm but it'll have to be 28mm header.
DA 150 header is closest.
ZDZ port 31x16...DA 27.2x16. Both 44mm bolt spacing. So with a little taper work at the ends of the header they should work okay.
Also i know someone makes a 28/25 teflon reducer. If anyone can remember who or where i can get one let me know.