2.7 Engine - Leakdown

[Avant]

I thought I would post my leakdown and compression numbers on my '77 2.7 engine. I guess it is time to do a full rebuild? The engine has 45k miles.

My original reason for doing a compression and leakdown, was that I could never get the fuel injection/timing dialed in without still having a poping sound, mostly through intake. This is with refreshed fuel injection and spark. Originally by compression was between 80 and 120. These numbers below come after applying 23 ft-lb of torque tightening all of the head studs. Nothing was pullled, they all took torque but the lower stud bolts all needed tightening, especially on 4 and 5. My compression is better in all cylinders now, the engine runs better, the popes and backfires are still there, but reduced..

3. 118 compression
90/65 leakdown. slight hiss heard through intake
2. 121 compression
90/86 leakdown. slight hiss heard through intake
1. 114 compression
90/73 leakdown. very faint hiss heard though intake
6. 134 compression
90/89 leakdown. very faint hiss heard though intake
5. 128 compression
90/89 leakdown. slight hiss heard through intake
4. 122 compression.
90/68 leakdown. noticeable hiss heard through bottom of engine