Well the 'early girl' is running again Many thanks to Peter Mac for the head gasket, as for some reason I had the wrong one
And the gasket is now clamped by ARP head studs, so it shouldn't be going anywhere...!
I also decided to remove the 280ZX airbox that was bolted to the front of the radiator (as it was restricting airflow to the radiator & engine),
and make & fit a new 3" intake pipe with HI pod filter.
And this is what happens when you run a lot of engine timing & remove a restictive airbox from the intake tract:
Instant lean-out & detonation = bye-bye h/gasket
This was not a totally bad thing to happen though as I decided to have the head checked over while it was off, & I'm was glad I did!
The reco included:
Repair of some water gallerys holes.
Chamber No4 had a crack in the roof(!) into a water gallery, which was repaired (I was wondering why it was slowly loosing water...)
Cooling system pressure check.
3 new valve guides.
Valve seats re-cut & Vaccume tested.
New valve stem seals.
Head surface.