2002 RD688s vs CV713 Dump Truck

[Mack Pup]

In the market for a Mack dump truck and torn between a 2002 RD688s(E7 350) or CV713 Granite (370 HP.)  The 2002 has 474,000 miles, 25,000 hrs opposed to the 2005 CV713 with 365,000 miles with 18,500 hrs.  Both trucks run pretty strong but the 2002 has considerable blow by that has me concerned. The 2005 has already had an overhead job and stated the other overhead checked out OK.  I've ran the JPRO on the RD688s and really couldn't get much information.  Both trucks seemed to be well maintained inside and out.  Mack CV713 has had two previous owners  and RD688s has had 3 owners.  I understand that the some Mack engines have out performed other Mack engines.  Both engines were clean with no oil slinging to speak of.  Neither owner will allow me to have a Mack dealership to check out the trucks due to insurance policy.  I would like to make this purchase with some confidence but that's seem to be hard to do.  

I would like to avoid running into any engine headaches right out the gate, if I can. 

1.  Which Mack truck would be the best purchase?

2.  What are some other signs of engine issues besides blow by and oil leakage?     

Video below shows 2002 RD688S engine blow by after running it hard for about an hour.  Truck got good and hot.

Any advice would be greatly appreciated.  

Edited June 25, 2018 by Mack Pup

[MACKS]

Well if the 02 has blow by when it's cold it's gonna be a whole lot worse when your working it,I would favor the granit,it's a much nicer truck to drive to in my opinion..

[Mack Pup]

Got'em both.  Thanks for the feedback. If you get a chance look at the blowby video and tell me what you think.