GU Y61 2.8 Power Isuue and smoke after new Head Install

[Dazz76]

Hi Guys

Hope all you guys and girls out there are enjoying your Patrol.

I have and old girl GU Y61 2.8 Diesel which blew the head.
I replaced with a new one and timed it all up and had No power and blew smoke like id made a smoke bomb lol.
Couldn't work it out thought maybe I had timing out so took to my mechanic who re - checked the timing and checked a number of things and suggested changing the turbo so changed it with no difference,
Did some research and advanced injector pump, got a-lot more power still not what I had before, runs well at 100 klm on highway but still smokes.
Going up hills still dies. Around low 60 klm around town and smokes a lot and takes awhile to gain power.
Wondering if anyone has any ideas how to fix or point me in right direction.
Many Thanks

Cheers Dazz76