I just ran across this thread and since I recently installed the Atomic EFI I thought I would share how I ran the fuel system.
I used the stock tank but installed a custom RobbMc fuel sender:
http://www.robbmcperformance.com/pro...78_gmsend.html
This is the fuel regulator I used:
http://www.summitracing.com/parts/aei-13109
I used this fuel pump it's about 1/2 the price of the MSD pump:
http://www.summitracing.com/parts/atx-e8248
I used the Aeroquip AQP fuel line:
http://www.summitracing.com/parts/aer-fcn0620
I ran the AQP line for the supply and ran the return through the original hard line. And finally, you will need two filters NAPA #'s 3270 before the pump and 3482 after the pump.