Distributor curve help needed

All street use, and using ported vacuum
OK. So my suggestion is to reshape the curve.
But you can start with simply reducing the initial.
I would not take it down to 15* just yet. If you do, it will probably be a dog from off idle to3000 rpmish when you stomp on it.

Here's what you measured.
upload_2021-7-16_12-26-48.png

Try something like 18* at 500 rpm.
upload_2021-7-16_12-33-46.png