Do you know what year the engine is?
The one thing that is not discussed here is the pointer on a 65 289 is on the drivers side of the timing cover, this may be a case of the wrong balancer, all is not lost, I believe you can use the balancer and timing pointer you have, you need to bring the engine up to TDC and install a timing tape to the balancer with the 0* line at the pointer.
Unless the engine is a 289 then that is a whole other can of worms.
I've got the same 289 front cover. Here I thought it was an oddity. Mine is a 69 block and the cover is original. Must have ran out of the 302 covers at the factory that day and grabbed some left over from the 289 days. Anyway I made it work by buying a really good timing light and painting the timing mark with glow white and then I could just see it behind the lower radiator hose.
That's all changed now from the engine rebuild last summer. Got a new pointer and balancer tape.