Will try and keep this short as possible.
My defender 110 300tdi required a new turbo so went down the route of fitting an alisport vnt full kit with intercooler etc. When this was done I had noticed a small oil leak from the head gasket (pre existing from turbo change ) shortly after I had a mechanic change the headgasket and at the same time fitted a forby tuning kit boost pin, timing advance ring and boost controller. He also adjusted the fuel pump slightly. After a short run the engine quickly overheated and before we knew it the head gasket had blown . Mechanic was mystified as he'd fitted loads of these tuning kits in the past and couldn't see what caused it. Subsequently decided the head gasket would need doing again but this time we would skim the head and pressure test as it wasn't done before, all came back good and was refitted with new gasket , bolts etc. On the first run it seemed to run hot but not go into the red , made sure everything was bled properly etc made sure boost controller was set right back so not overboosting and took for another run after a short time it overheated and immediately blew the head gasket again.
I am now completely stuck and don't know what the next step is, I'm thinking I will probably need a new head as realised from receipts it had previously been skimmed. Just don't want to spend out on a new head and knacker it immediately because I'm missing something. Would the tuning cause these problems with a vnt ? Have heard this could be a problem but now can't find the thread. Any help or suggestions be much appreciated as feeling like I'm banging my head against a wall!
