Any Way To Cheat And Find The Right Timing Tab?

[BRL]

I put this 350 SBC together and didn't bother to set a tab on the timing chain cover before bolting on the heads.

Of course the crankshaft and harmonic balancer line up together with the key, but I'm hoping that there is the right tab as an aftermarket piece at the auto parts store without having to shove something in the spark plug hole.

Or am I just out of luck.

...yes I'll clean all the gunk off either way.