The 10mm are the old ones, the 7.5 are the newer style.

The design was changed to shield more of the surface area of the nozzle from combustion.

Go with the 7.5, it'll save your nozzles.

__________________
1984 300D Turbo - 4-speed manual conversion, mid-level resto

1983 300D - parts car

1979 300TD Auto - Parts car.

1985 300D Auto - Wrecked/Parts.


=========================

"If you don't know where you are going, any road will get you there". Lewis Carrol