627B How do i adjust the clock on this scraper?

How do i adjust the clock so both engines can talk to each other, I have a 1978 627B scraper and i have replace all the electrical wiring all 200 lf of it and it still wont run right

serial number please
I am a bit confused your saying the engines wont talk to each other.
These engines are not electronic,(unless they have had an emissions update) they are mechanically governed engines and the rear engine is throttled up and down by an air slave cylinder controlled by its own throttle pedal
if the engines are not running properly have you checked the basics, air, fuel, valves etc
You also said you replaced the electrical wire. Do you mean you changed the harness between tractor and scraper all the way to the rear engine/transmission.
Are you in fact chasing a transmission shift sync problem between tractor transmission and scraper transmission
What clock are you talking about?
Do you mean transmission syncing either the shift card or rotary switch depending on serial number

Really need the S/No of both the tractor (front end) and the scraper (rear end), just in case someone has been playing "cut & shut" with a front half from one machine married to a rear half from another. They will be different and there are four different options for each one...........

Getting those back trannies synced up will be hard work and require a good bit of knowledge.
Not for the jobbers sort like me!

1st check both trans mechanical-hydraulics: Filters and Screens looks for clutch and metallic particles. If one of the transmissions has basic wear issues the electrical controls won't function correctly.