My compression was within 5% and optimal leakdown, but my head lifted with a t3/t4 on 7lbs. Blown head gasket can lead to big problems, better to be safe than sorry.Spend the extra 120 dude. The t3 turbo I have is a perfect fit for our sized motors, even though I loved my t3/t4, either of the two is a good choice.
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New condo pattaya

 

Stock Y8?

Whoever tuned your car put a Z6 timing map on it. Happens all the time. Too much timing will cause headlift in the smallbore Dseries engines, really doesn't have anything to do with the psi.

OP, if you're going to stay with the stock engine, however many PSI it will take to make ~215ish mark would be where I would stay with. Correct tuning needed obviously.

T25 you will probably need 10-12psi to get to that mark. PSI really isn't what blows engines, bad tuning and detonation does.