crank but no start

[laoz]

Hi
I have a 2005 e350 6.0lt, a few weeks ago it had an oil cooler failure, so i put on the new oil cooler, egr delete kit , stc upgrade ( in high pressure pump) new diesel filters and oil filter, after everything is put back together like it was, i cranked but it doesnt start, now i dont know where to start checking to see where the problem is, any sugestions ? thank you