Using your method, it's hard to say.
I have never used your method.
And I can't get sense of how you wrote it;
In the same sentence, the piston is at the top, then it is coming up. So, wth stroke is it on at what time?
Looking at the factory 318 cam specs, with the cam installed 4* advanced, the intake should be opening at about 12* before TDC and closing 48* After Bottom dead center.
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The usual method for estimating cam timing, is to set the cam at split overlap, then read the balancer.
This is done with the piston at TDC-EXHAUST. Normally I rotate the crank until both lifters have risen to the same height, using numbers one or six. Then read the TDC mark on the balancer, having previously proved the TDC mark.
That reading should be in the window of 8* advanced to 4* retarded. The engine will run quite well anywhere in the window.
The more advanced the cam is, within the window, the more low-rpm power it will have. As the cam is retarded in the window, it will trade away that bottom end power to get some operating rpm at the top.
If it is outside the norm, that would be grounds for digging deeper.