Definitely, open the crank induction timing to at least 200degrees if you want to increase your lateral intakes to 120-125degrees and your exhast duration to 165-170 degrees. With some simple trig, you can calculate just how much to cut left, right, or both to increase the total duration even before you put the Dremel to it. To verify your work and se whether you achieved you target induction pofile, use your degree wheel of course.

Since your engine is a side exhaust, seriously consider reshaping your lateral intake ports to direct the fuel-air charge away from the exhaust port. (These lateral sleeve intake ports are not "lateral" in relation to the centerline of your engin, in reality, they are posterior and anterior to your engine centerline.) Camfering the ports to direct the fluid flow up and away from the exhaust port is a start, and camfering the upper part of the ports will also increase their duratrion to your target profile. Additionally, you will have to reshape the block passages to also help the Schnuerle effect of the loop scavaneging and directeing the fresh fuel-air charge away from your exhaust port. Not an easy thing to do in a side exhaust engine.

As for your xhaust port, the shape of the side exhaust port is as you put it in the engine forum, quiant. Actually, it is seriously inefficient. I do not know the dimnsions of that side port nor how much material you have to play with, but to help with exhaust flow out this port, the best you might be able to do is reshape it in a flattened diamond shape or a flattened pentagram shape. You will have to similarly mod your pile manifold so that the modified exhaust "slit" now matches your engine's exhaust.

Post your your progress in the engine forum too, though we mostly mod rear exhasust engines, many of us are intrested in how one would mod a "quaint" port configuration and port shapes to improve output. Also, aside from letting us know what timing profiles you achieved, let us know what your new port areas are in relation to what ther were before you started.