Before I start, I know that there are tons of threads already about timing cams, and let me assure that I have gone through loads of them already to try and figure out this problem.
Back-story: I followed Wayne's procedure for timing the cams...that is, I used clamps on the idler arms to fully tension the timing chains, then timed the left cam; and then timed the right cam. After running the engine through several full 720 rotations, I found the timing readings on the dial indicator were consistent: 0.47mm for the intake valves at overlapping TDC for cylinder #1 and cylinder #4. Note of procedure, this is a 1975 2.7L CIS with stock cams (intake valve overlap range = 0.40-0.54 mm). From my untested understanding of this procedure, I felt that these readings were right-on for the timing and felt ready to install the hydraulic tensioners.
Keeping maximum tension on the idler arms, I slid on the tensioners and let the pistons pop into place. NOTE: that the tensioners are exerting less pressure on the chain than the clamps I was using during the timing.
Here's the question...due to my inexperience and desire to not destroy my engine once it's finished, I have the tendency to overthink and over-check everything. So I checked the timing specs again with the chain tensioners installed and found a discrepancy in the readings...they had changed from 0.47mm on cylinder 1 & 4 to 0.51mm on cylinder 1 and 0.60mm on cylinder 4 at overlapping TDC.
Any thoughts? I am just trying to decide if I have made a mistake somewhere along the line that I need to try to remedy. I tried to keep maximum tension on the chains while timing and installing the tensioners...does the change in timing readings indicate that I need to re-time the cams? Or are these misgivings unfounded? Thanks for helping out this first-time engine builder finish fixing his baby.