Having had a smacky sound from the left cylinder of my newly acquired T3 California I did some probing and discovered compression way down which turned out to be blown head gasket. All looks well other than this. However purchased new head gaskets only to find when beginning to reassemble the head that the gasket doesn’t quite fit. Not exact same pattern as the original. Checked the piston and barrel classification which is C and measures the normal 83mm. Anyone had this experience. The push rod holes would line up but the smaller oil way to the lower left is a couple of mm out and virtually all the stud holes are 3-4mm adrift. Planning to send my original back to GB with the new gaskets to see if they can shed light on it. Could be just a case of wrong gaskets sent.
If they’re the wrong gaskets I can’t imagine what else they’re for. Tolerance group ‘C’ has nowt to do with it. There aren’t equivalent variations of head gaskets to match. Does the cylinder hole line up along with the push rod holes? Been a while since I last did one but I do seem to recall some small anomalies. Oil drain hole not quite lining up being one I think.
Just sounds like the wrong gaskets.
Square fin motor has different stud spacing,
sounds like that the gaskets you have are for a later motor
Ah well I didn’t know that. That’d do it then.
Checked with Supplier and Apparently poor manufacture. Checked the new base gaskets and they were correct proving I didn’t have a duff engine. All good now with new gasket in place and engine running lovely. On the matter of compression I tested both sides initially and the good side was measuring just over 100 psi and the poorly side, around 40 psi. Both are now just above 100 psi. Is this compression to be expected.
Tested my T3 last week. Got 150 both sides - I was happy enough they were the same and didn’t check the units but presumed it was PSI. My tester is a non-calibrated cheapy so may in itself be a bit here and there.
Good grief … 
could be that mine is a little on the leaky side. Interested to hear anyone elses results
Did you do your compression test with wide open throttles?
Who me? - Yes, always.