I recently replaced the nozzles in my injectors. Four of the nozzles were 265 and one was a 442. The 442 was in better condition than the 265s. Seemed to burn cleaner than the 265s. Any ideas on how these are different?

I do not recognize either of those numbers.

What Vehicle/Engine they are used on may be a help.

The Stock Nozzles on the 617s have drilled Passages in the Pintle Needle. Later Bosch Nozzles and Monark Nozzles have a Facet (a flat ground onto one side of the Pintle).
Both are for Idle and low amounts of injected Fuel.

To the best of my knowlege Bosio Nozzles do not have either of the above features.

Apparently from the Injectors I had on my Car and the ones I have pulled from the Junk Yard the Nozzles with the drilled passages can get entirely Plugged with Carbon. That would be harder to happen with the Facet type Nozzles.

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84 300D, 82 Volvo 244Gl Diesel