"How much power is enough"...take #2

[Dimis]

You could probably afford a little more.
The AP suspension set up looks a tad more advanced than a 60s ladder frame AC.
I suspect it would cope just fine.

However if you did want more, my humble tip is do it by adding cubes, and matching cam and heads. Don't just jump to a higher cam, it potentially could run like a dog at street rpm. 800-2500rpm.

Either way, the attention to detail you are putting in your car, it's going to be a sweet little champ!
Waiting with baited breath for the final outcom me.