Dumb question. Confirming cam position at TDC for timing set install

I just installed my cam and I'm ready for my timing set install. In the past I've never put much thought on cam position when I'm installing timing set. I lined up the marks in the gears and confirmed TDC on #1. Slid the timing set in and rotated a couple times to confirm that nothing is binding up. Everything rotates smooth so I thought I was good to go. Then I get to thinking that the cam could be In 2 possible locations when #1 is at TDC. 0* and 180* opposite. At both the cam lobes are positioned in a way that the lifters are fully down in the lifter bore. I realize that either way I will install the distributor on the compression stroke of #1 TDC. Thoughts?

Not that it matters but I'm working on my 66 200 six.

you are overthinking this. when lining up the timing marks on the gears, as long as they are lined up according to the factory, the timing is going to be close enough that when everything else is put together then engine will run.

Disconnect the coil. Remove #1spark plug.
Bump the engine over by hand or with a remote switch while holding a finger over #1hole.
You will feel the air pushing out on the compression stroke.

Hi, as mentioned, mark to mark will be right. The cam cannot be 180 out. It turns 1/2 crankshaft speed. It is keyed to be installed one way. Good luck

Why take a chance, for 22 dollars you can do it right and dial it in..You or they may have made a mistake, it happens.
Is the spacer installed behind the cam pin with the inside bevel toward the cam journal?
Make sure that the oil galley plug is installed in the block near the cam sprocket area.

Also check out the engine build videos at the top of the forum echo1955, he goe s step by step in Degreeing in the camshaft correctly. Good luck