Tractor Repair: timing of a IH 444

Question
i have a IH 444 that i got off a friend. I have replaced the Injector pump, and Injectors. We have lined up all the marks on the cam, injector pump gear, and flywheel making sure the we were on the compression stroke. The ole girl just want start.

When I checked the compression #1, and 4 show 400Lbs.2, and 3 show 200 lbs.

How do I make sure that the timing is where it is suppose to be?

Answer
Your compression problem is a major contributing factor.....you need to shim your head or have it re-milled and check your rings. Make sure the injectors are BLED BLED BLED, and then use a little starting fluid. If you are indexed correctly, she'll start.