need a little help with my 6V92

[cattleman]

I think I have found the right place to get a little help. I have rebuilt my 6V92 that is in a dump truck. The former motor had a vent it, previous owner forgot to check oil! The motor I took out was a silver block that had 9G90 injectors. The block I got for a builder was also a late model silver however it had 9A90 injectors. Unfortunately I started taking one of the 9A90 injectors apart and lost a part. I have been told that the 9A90 are the injectors I want to put back in. mean while I have found a source for some 9N90 injectors but my book has no info on that injector. It stops at 1987. Would the 9N90’s work and what should I expect performance wise between the three? By the way the motor is a mechanical unit.

[NJT5047]

Someone on this board may have an answer for you... sorry , but I don't.  You may wish to check out the "Detroit Diesel" group.  They will have an answer for your question.   The site is a Yahoo Groups thing at:  http://autos.groups.yahoo.com/group/DetroitDiesel   You'll have to join to post, but you will find a good bit of DD specific information. 
I can add that the reason the MUI injectors stopped in 87 is likely due to the introduction of DDEC electronic injectors. 
Good Luck, JR

[Geoff]

I've never heard of 9N90's, but I know the letter in the injector type indicates what the injector is timed at internally.  If your engine came with 9A90's you should put 9A90's back in.  9G90's should also work, but the 9N90's may be built for smog-cam engines or some other special application and may not work in your engine.

--Geoff