Blown Head Gaskets 4.7 V8 1999 Amazon Petrol

I purchased this car 2 weeks ago and had the radiator replaced soon after purchasing as the car was tending to overheat. Now in Calais France with caravan in tow and blew headgaskets. Have option to return car to UK for repair or have repaired here which is my preferred option. Engine was replaced 4000 miles ago with imported JAP Engine

Could you please tell me how many hours labour approx. it would take to do the job and approx. costs replacement parts

I need to make a decision toda Thursday 25th July.

Thanks for your help

Regards,

Serg stranded Aussti in France

Serg