"Dot-to-dot" is crap. You're relying on about five different machining operations all being done correctly, with little room for error or tolerance stack-up, and there's a reasonable chance that at least two of them are being done by the Communist Chinese. I won't put an engine together any more without "degreeing" the cam. I rarely ever have to "fix" a problem...but I also never have to deal with mis-timed cams as part of my diagnosis for driveability issues, either.
Verify cam timing. This is not a precise deal unless you install the whole dial-indicator-and-degree-wheel tool set; but you could maybe eyeball it to see if it's close.
Put the #1 cylinder on TDC-EXHAUST. (Normally, when you want TDC, you want TDC-Compression. This is not one of those times.)
Both valves should be open on overlap--just barely open. The intake valve should be open just a little more than the exhaust valve. This is easier to see on solid-lifter cams, because the lifters don't bleed-down. Give it a go, see what happens.
What was the piston-to-deck clearance? Excess piston to deck--often called piston "down in the hole"--will kill compression ratio and compression pressure. Worse, most aftermarket replacement pistons are deliberately "de-stroked" (a misleading term that has nothing to do with crank stroke) so they're an additional .010 or .020 "in the hole".