I think that light weight bar that comes on the Husqvarna T540 is the same mount as your Dolmar 421. Teck lite or something along those lines. That would be a 9 tooth nose.I have very limited options at 3/8lp without filing out adjuster and oil holes
What is the problem with this one? A pro91 oregon is real tight with a 56dl loop as well.
http://performanceoutdoorequipment....ducts/total-2-bar-t677ml3-x-14-3-8lp-050-57dl