G'day awwl,

Im currently looking to buy a GQ 93 petrol 4.2 from a good friend. The twist is, that the "head" apparently needs a recon. The theory for this is its running on gas (HOT) and the compression is down from the cylinders when measured... But! the compression is equal across all six pots. No water in the oil. Advise from back yard mechanic is that the valve seats drop into the boiling hot cylinder head thus not giving a good seal with the valve. ?? Or maybe the bore's have worn....but equally?? across all 6??
Thought i'd throw it out thier, see if anyone else has seen or experienced this.
Thanks for reading