hp and tq estimates?

I also went with a 650 Mighty Demon on my 340, but it's not stroked. I have a 1" 4 hole spacer so it runs smoother as per Don's advice.

If you wanted a street cruiser, I would go with Don's advice. He knows the BG carbs very well and I'm sure he went over the engine build specs, tranny, gears, exhaust, stall, etc. with you. If you didn't do that with him then you should. I believe science over the 'bigger is always better' arguement after reading and talking physics with Don. You can always go bigger for ***** and grins.

Read about VE = volumetric efficiency on his site. With your build I would think that your VE would be somewhere around 90% +/-2%. Which would require 682 +/-15 cfm at 6300 rpm. How often are you really going to be at WOT at 6300 RPM in a street car? If you plan on racing you maybe able to exchange your carb with Don to the 750 or 850 Mighty Demon.