I preface what i am about to say with I am in this thing to the end and it will be right and the way it should be without compromise when finished. That said last week I started noticing the signs of head to cylinder leak,,,again!!. So I whistled and out came the engine... again. Seriously it does come out in less than an hour now and the engine was stripped to a long block in another 40 minutes. I did a leak down test of each cylinder with a 100psi Moroso tester while squirting soapy water at the cylinder to head sealing area. I saw what I expecting.. plenty of big bubbles. I also could feel a large amount of air leaking from the intake valves even after popping the valve with a plastic mallet to clear any carbon an such that might have been between the valve and the valve seat. Still the valves were leaking. Between the cylinder to head leak the valve leaking and anything getting past the rings each cylinder had 18-25% leak down which is terrible of course. My goal on engines I have personally built is 2-3% max leakage on a new high performance engine. I called AA performance the builder of the heads. (Hoffman heads and Type 4 store heads (which are made by Hoffman) were all back logged until late spring ) that is why I tried the AA heads. My engine builder and myself are baffled. He checked and double checked the heads but all the problems seem to be in the heads. Jonathan at AA was very nice when I told him of our situation and asked me to send the heads back which they should arrive on Tuesday. The short block is headed back to the builder to re-check the flatness of the cylinder seating deck just to cover all our bases. I am going to keep smiling and seeing this through to the end which when I arrive there will be a gratifying experience. I firmly believe the payoff will be just short of amazing in the amount of power I am now sure this engine is capable of. Patience is the key it appears.