Have you looked into running vacuum advance hooked to the manifold?
This will give you favorably high initial timing and will "lessen" or drop the advance down to where it runs only on your "mechanical curve" under high load.
The result is good low rpm part throttle response, good idle and good cruise power.
The other result is when you have more fuel-air in there under mid to full throttle when the mixture is "burning faster" actually just more filling cylinders resulting in less needed timing, you have less timing which prevents knock under load.
You will probably like it if you get it dialed in using that method.
There are a number of good threads here regarding using manifold vacuum and alternately "port" vacuum. Depending on the curve and build of the engine, both have their place. There are lots of debates as well but many have had good results with manifold vacuum advance. Essentially running manifold vac advance is like having a crude MAP sensor on your advance system.
There are a few tricks or setup details to get this to jive with your engine needs. Your mechanical curve needs to be right for the engine and then you add in your vacuum advance for idle quality and part throttle driving. You must limit your vacuum advance "distance" or total amount and you must adjust the spring pressure in the vac can on the dist so it will respond favorably to your manifold pressure response from throttle input and engine load. You basically create two curves. One mechanical and one based on MAP. They are directly related because they depend on each other to yield total timing at a given rpm / engine load.
Some of the EFI guys on this site can shed more light on the need for mixing MAP inputs and mechanical or predetermined curves combined to yield favorable timing events under varying conditions.
