I'm wanting to put duel strombergs on my flatty and really like the look of the mechanical fuel pump. I was wondering will the pump keep up, also will crab distributor work for setup, read somewhere should go with electronic but would like to keep the crab.

 

I don't know if the original pump will keep up or not. I installed a rotary pump with my fuel tank relocation and a pressure regulator for my original two barrel carb.
What I did to preserve the original look was to take the original fuel pump apart and gut it. Remove the valves and all linkage. Then I made a sheet metal diaphragm and assembled the fuel pump using the metal diaphragm to keep the fuel contained in the upper chamber only. This way the fuel from the rotary pump goes through the fuel filter bowl on the original pump and through the original pump ant on yo the carb. It looks original and if you didn't tell anyone no one would know it wasn't stock. I've included a picture.

 

you will be fine with the stock fuel pump as strombergs like 2.5 to 3 PSI, you may need a pressure valve to decrease the fuel pressure to avoid pushing gas through the needle and seats. You don't want flooded carbs or worse gas leaking out carbs near the generator with the brushes sparking!!!! Cheers.