Super tuning car runs good shooting for great

Sounds like you're on the right track.

A good way to set initial timing is with a vacuum gauge. Loosen the distributor just enough so you can turn it and hook up a vacuum gauge to the carb base plate. Start the car and with it running at idle, increase the initial to where you get the highest vacuum reading. Then, back it off one degree and lock it down. You may have to adjust your total again but it probably won't be too far off from where you are now. Then obviously you have to re-adjust your carb idle settings but again, it probably won't take much adjustment.

From what it sounds like, your bog has less to do with timing than an accelerator pump issue. Are the pump arms adjusted properly? Do you have different cams to try? There's a pump cam chart floating around that shows the delivery characteristics of the individual cams. If you only have the one cam, switch the position to see if it helps. Pump squirters can also be changed out.

Sometimes you need a longer duration cam. If you have the assortment, put the blue one in and see if the bog disappears. If it does, then start backwards with cams until it bogs again the you know where you need to be. Tuning accelerator pumps can be frustrating, more adjust, drive and repeat.

The 6.5 power valve is probably fine if your idle vacuum is over 10". You wouldn't want a 4.5, it would be dumping extra fuel. Is it blocked in the rear?