1hz head gasket

Martyn - If you install an aftermarket turbo, the compression ratio should be reduced by the fitting of a thicker head gasket.
I presume this has been done? The crowd fitting the turbo should know to do that.
Overfuelling will be obvious by black smoke pouring from the exhaust under heavy acceleration.
Get someone else to drive the 80 series and get them to accelerate hard while you follow it reasonably closely in another vehicle.
The exhaust should only show a slight haze of black smoke under acceleration.
If the black smoke is thick and very visible while the accelerator is being floored, then it's overfuelling.
The fuel injection pump should have been adjusted to provide more fuel when the turbo was fitted, because the turbo delivers a lot more air than a naturally-aspirated engine can suck in.
However, the fuel delivery has to be in line with what is required for the amount of air available in the combustion chamber.
If the pump has been adjusted up too far, this will then create an overfuelling situation.
There should be no reason to buy a new head if the old head has no cracks or isn't badly warped.
It certainly pays to have the head surface ground, the valves ground and valve guide-to-valve wear checked, when the head is off.

Cheers, Ron.

Don't even think about a refurbished head, get a brand new one from All Head Services in Victoria. Ph: 1300 41 61 81. They will send it to you complete with valves and ready to bolt on.
http://www.allhead.com.au/ (Site sounds dubious I know)
I have no connection, just a very happy customer with there price and service.

Cheers Tony.

Do you know what boost pressure you were running?
Any indirect injection diesel turbo shouldn't be going much past 10-12 psi due to their already high static compression ratio.
Also regardless if you go new head or recondition your old one, get new head bolts and torque down appropriately.
Regards Andrew.

My 100 series 1HZ has been looked after for the last 14 years by Cross Country 4x4 in Edwardstown, and is still going strong. It has a Schwitzer turbo from almost new, and a Cross Country top mounted inter cooler now days. I suggest you talk to them if they are not already in the mix.

Update on the 80 series head.
4 out of 6 cylinders cracked. So a new head & all the bits is on order. Will be another two weeks as machinist is still on hols.
No idea on dollars yet!!!