Bking:
Asked a Scania “technician” for the firing order of a 5 cylinder piece of crap the other day to set the tappets.
His responce was"they dont have a firing order you got to set the tappets using a computer"
WTF?
Find number one and turn the crank 144 degrees and thats it?
But no you got to have a Computer!!!
The 5 cylinder is a royal pita I think its 144, 288, 144+288m 288+288 and er thats it no computer needed, still waiting for the trun tool I asked for a year ago!
So I havent actually done one yet 
If its the older pre common rail engine its even more complicated as the injectors need setting as well.