DD 60 Series just need advice,

Hello all here is my deal, I bought or stole an 04 Columbia in march form the local used freightliner dealer, it was an ex penske truck, I have a friend at penske and he dug up all the info in the truck, it was in an accident and everything external on the engine was replaced, so lets put it this way, everything that is bolted to the block or in the compartment was replaced at 379500 miles, I bought the truck with 388000, i know what you are thinking what are you nuts buying a truck that you know was wrecked, but if I throw out what I paid it will make sense, anyway I am at 419k now I am a maintence person so oil is changed every 10k air fuel etc all done when its time, the truck runs great and has really good power and I am getting 7 mpg almost all the time, there is one thing though and it has me a bit concerned, shifting from 9th to 10th every so often like once a week it will cough, it is brief maybe 1.5 to 2 seconds almost like it sucked air, blow a puff of pretty black smoke then all is fine, it really wont happen for another week give or take, so am I screwed, I do have a warranty from frgtlnr and it is extensive, so hopefully if it is a major deal it will be covered just want some input here b4 I go there. Honestly it is so infrequent and brief it really dosent bother me that much, also at this point should I be thinking of having the shop go round the rack and do a check up even though all is well besides the cough.
Thanks in advance
Dave

 

its an early VGT and You hit it on the head I didnt mention because it would have been too long, but if I let it rev to 1800ish in 9th which brings me to 65 MPH and then make the shift it never happens, I am a gentle driver so this is un natural to me shifting easy around 1550 16 is more my style, (no I am not a lugger LOL) but that is what is happenning so this is common, or does it happen only on wasted turbos or is it because it is a vari geo, and yes I am not sure of the numbers but 10th is very far from 9th, it has taken me quite some time to learn how to drive the truck right, as for the past 17 years I have been in Macks and only Macks which are quite different from this truck, But I will say this I expected this to perform like a line truck, and I have been pleasantly surprised, I have it set to 76 mph, and am impressed with the power I am a flat bed o/o and am heavy most of the time, I live in Mass and am runnng the N.E. always so hills are part of the deal, tell you what this truck with 47k on the deck would out pull my 02 ch613 with the e7-460 all day long, and as far as the ride goes well so far it has been good not as good as the ch but much better than everyone said it would be, all in all I do about 3000 a week here in Newengland Ny and NJ so he running is hard and the roads are worse, and this thing hasn't griped a bit, they tell me it is 515 hp but there are 2 stickers on the cover one says 475? @1800 then the other one says 515 so i really dont know someone said if the crusie is on it's 515 but 475 on the pedal, this makes no sence to me, and i feel no difference between the 2 but either way it pulls good and is doing very good milage wise,, I never thought I would say it and not be lying but I am really happy with My 04 columbia, Hey thanks so much for the response.

 

oh yeah on more thing that has really amazed me. this truck leaks nothing, I can idle for 4 hours and the spot where i was parked is dry, my macks leaked oil wth 10 miles on them, yeah there is some oil on the pan bolts but never enough to drop, it amazes me. Park it over the weekend in the driveway and no cardboard needed honest 419k on the motor and it is dry, weird, and i should probably find some wood to knock on b4 i screw my self.