Hello everyone I have a 66 c-code c4. In the progress of changing out 2brl. carb.for performer 500 cfm carb. and intake.So while I have manifold off I noticed I could spin all push rods by hand except #2 intake and #3 exhaust.All lifters were flush except these two who were 1/2" raised on lifter.Last time I adjusted did with engine running.Should I back off both as to twist push rod? No problems before I pulled manifold .#1 on BTDC. Thanks for any advice.