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What’s up everyone! Been having an issue with my Gen3 5.3. 173kish miles torn down to rebuild. Did TSP 224/228 .660 lift cam, Delphi LS7 lifters(now has Morell 7717, which you’ll understand in a second), 7.400 pushrods, BTR dual springs, new cam bearings, factory oil pump, gaskets all around, only thing not replaced was bottom end parts, pistons, bearings, etc. Speed engineering headers with 3” exhaust, CAI and on a little bit of nitrous. Trans is built with a Circle D converter. So here’s my issue! Cylinder #7 has had a god awful tick, sounds exactly like a lifter tick, which is what prompted the new lifters from Delphi to Morell on the off chance one was bad. They weren’t. Pistons looked fine, bottom of head looked fine, springs are fine, everything everywhere looks fine. No marking, no burns, nothing. Cut open oil filter and looked like someone sprinkled a pinch of pepper in it. No boat flake or copper in the pan. I’m lost. Have had 3 different mechanics and about 10 different people with ideas but can’t seem to find a sign of an issue anywhere! So here I am asking for more help or somewhere to look that I haven’t been yet. I have more to say but it’s just thoughts that we’ve run through. So if you’ve made it this far, let me hear it cause I’m lost!
When you measured for proper push rod length to get the correct lifter preload, (a) what lifter preload did you target, (b) what preload did you achieve, (c) how much variation was there among valves especially the 2 #7 valves since you don't say whether it was the intake or the exhaust, and (d) what was the measured push rod length that gave that measured preload? Why 7.400"?
When you swapped the #7 rockers with another cyl, did the noise stay on #7, or did it move with the rockers?
When you turn the motor slowly by hand, do you hear any noises? even something that seems OK at that time; like maybe a rrrrrrreeeeeeeeeekkkkkkkk kind of sound?
So didn’t change rockers to get that out of the way. And couldn’t tell ya if it’s intake or exhaust valves. Just know it sounds like #7 only. From what I read and understand 7.400 is the average length for a build(which is why they come in all the kits). First go around had 7.400 in it with a 6.0/6.2 head gasket which I believe is .055? Thick and went ahead and put 7.425 in which put it at that threshold of preload, still ticking. Second go around on the lifters when the morels were put in the mechanic said 7.400 were correct and also went back to a 5.3 head gasket which is .048 I believe once again(but I didn’t put an eye on preload measurement) my only thing with that is what’s the chance that #7 with 2 sets of lifters and 2 sets of pushrods would still be only #7 if the preload was off. And not the other 14 or 15 pushrods also. Will also add good oil pressure sits right at 40psi idle and just goes up from there when under a load and has never fell off. Also never heard any sounds when turning motor over by hand with the assembly.
The tick does go with rpm but doesn’t seem like it is a piston tick/knock if that makes sense. So not 100% rotation speed. When sitting at idle with tick can put it under a little load to say 2k rpm and it will rise but doesn’t sound like it goes exactly dead even with rpm speed.
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Looking for help 
