I would install the proper valve springs on both sides. Yellow springs are Z06/LS2 style and are only about $60 new from SDPC.com. Are the head castings the same?
The factory rocker arm trunion bearings are notorious for failing as well. Get the Comp Cams trunion rebuild kit which is about $130. Takes about 10 mins per rocker taking your time with a press. Very cheap longevity/reliability upgrade. I do this on all the LS motors I build.
Also the factory LS2 chain should be run with a GM chain tensioner. As suggested you may want to make sure there is one in there. Good time to replace the crankshaft seal for no future worries. Order a new crank bolt or get an ARP reuseable one as well.
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Project: 1969 Chevelle, alum 5.3, GTS76 turbo, Chiseled Perf A/W intercooler, Holley Dominator EFI, Davis TC, JRi coilovers, 14" brakes, T56 Magnum. CTS-V Recaro seats!
Coffey Fabrication Nashville, TN doing the fabwork! 800rwhp+/25mpg+/9's@150mph goal 
https://lateral-g.net/forums/showthread.php4?t=52976
1993 Mazda FD RX-7, built LS7, T56 Magnum, Holley HP, Davis Tech TC, 8.8" 3.73 Cobra IRS diff, DSS axles, Ohlins coilovers, big brakes.
CCW 18x11 front 315/30/18's and 18x12.5 rear on 335/30/18 RA1's, 2850lbs
10.31@137mph 165mph Shift-Sector 1/2 mile speed
441ci AllPro headed motor and 200lb weigh reduction in the works....
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