Incoming 3406C - Engine locked up where to start??

No do not mix match parts they will bolt up but have differences that will cause multiple performance problems.

I really need the arrangement numbers on the 4MG but a short list is
OR-3423 fuel nozzles
175063 turbo or 177148 (both Borg Warner and very affordable)
8M-9141 Govnor spring.

If you have the 18 degree pump cam leave that alone if not find a meter and set it to 18 degrees static start the advance at 1400. DO NOT GUESS AT THIS

You’ll need to change the torque group in back of pump too while it’s off

 

I did not get the 310 HP engine. I was looking at two trucks, sisters, both 1989 White GMC tractors. The one had the what I guess is the original engine, the 4MG 310HP. The other identical truck had a Cat Reman 3406B 425 HP, I wound up getting the 425 HP. Both trucks were running driving trucks and both engine looked and sounded great. I paid $1500 more for the reman - hopefully I made the right choice. Here is a picture of the tag. I appriciate all of your input and look forward to what you think of the 425 reman. I was not able to verify the mileage on the reman, I should be able to get the maintenace records they were just not available today.