Firstly, make sure there are no obvious differences in journal diameter or oiling between the two cams and their respective heads.
Then you should check for runout, particularly if the cams are unknown to you or you suspect you bent them by cooking the head. Put the cams in some V blocks - just use some chunks of aluminium - and set up a dial indicator on the centre journal. According to the TSRM, you can have up to 0.03mm runout. Any more and it becomes a nightstick, tent peg or anal dildo.
As for whether there are any subtle differences in lift or duration, I suspect you'll need to work this out for yourself. Here is a basic way I use.
Put the cams in your stuffed head.
Put a degree wheel on the front of your cam lining the zero opposite the peak of the first cam lobe.
Then set up a dial indicator on the first cam lobe so that it reads zero.
Grab some graph paper. The x axis should read degrees 0 to 360, and the y axis should read lift (in whatever units you desire).
Mark current measurement on graph paper.
Turn cam by 10 degrees, make another measurement and plot it out.
Repeat process till you get to 360.
Repeat above process for other 3 cams.
Alternatively, you could give your local cam shop a call and see if they will do it for you on their cam doctor.
Now you can compare and contrast the cam profiles.
HTH
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