If you just replaced the cylinder head, and I'm assuming you got a new head with new valves and the whole assembly. 2 new cams, did you replace the timing chain and chain tensioner? The minimum compression for a used engine is 127psi, Compression with a new head and components should be up around 178psi. 115 is definitely too low and 125 sounds too low too for a new cylinder head.
The diagrams on All Data look different than what I would expect. This is a dual overhead cam, correct? And does it have a 2-chain setup? The 1st diagram below is supposed to be the 2.7liter and so is the 2nd diagram, but it only shows 1 cam on the 2nd. I think this service information is wrong. But if you have low compression like that, I'd say the timing chain might be off by 1 or 2 teeth on either cam, or the crankshaft. But they don't give any information as to where the timing marks are. Same information on All Data and Mitchell. But if you reused the old chain, and/or tensioner, that might be where things went wrong. The low compression is the clue to what's going on.
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Wednesday, June 8th, 2022 AT 7:04 PM