time frame for MUI to DDEC change?

[bevans6]

I don't know if I will need to rebuild or exchange my 8V71 yet, but I like to troll around craigs list and places like that looking to see what's out there.  I want to check my understanding of when DDEC came out.  I am pretty sure that just about all 8V71's are mechanical, is that a fair statement?  I think that early 6V92's were mechanical, and they changed to DDEC in the mid 1980's, does anyone know the timeframe?  Was there a long overlap where mechanical and DDEC were both available?  If I see a "silver" 6V92, could it be either mechanical or DDEC?  Most ads don't say, and I don't want to be calling all over just to ask on a whim.

Thanks, Brian

[Sam 4106]

Hi Brian,
Yes, a Silver 6V92TA can be either mechanical or DDEC. The first year MCI used Silver 8V92TA DDEC in their buses was 1987 but I don't know if that was the first year that they were available. The Silver 6V92TA serial numbers start at F83425, according to information on this board, but if an advertiser doesn't list whether an engine is mechanical or DDEC they probably don't list the serial number either. You probably already know this, but if you switch from mechanical to DDEC it will be more difficult and costly if you don't get all the wiring harnesses and accessories with the engine.
Good luck, Sam MC8

[bevans6]

Thanks, I had 1985 - 1987 in mind as when the change occurred, but the serial number helps a lot.  My goal is, that if I do change that I stick to mechanical, for all of the reasons you mention.

Brian