318/360 flex plate

Hi all,
I'm scrolling around and I noticed the doing a 360 swap will require either the 360 torque converter OR flex plate. So if I am already using a 360 torque converter in a 727 will the stock 318 flex plate be good?

Also, should I replace the stock 360 harmonic balancer with another stock unit or is there a more preferable aftermarket unit?

It's basically a stock 79 360 truck motor with a 4 barrel and headers. Nothing radical.

Thanks
Tim