There is no BPW constant in the 7427, only Injector Flow Rate, but as I mention before you cannot change it until you've settled on a injector/fuel pressure combo. In one of my replys I insisted you quit fumbling with different injectors and fuel pressure and just pick the combo you need for your HP requirement, even gave you the link to the injector calculator.
First, what HP number is your engine combo good for 350hp? If so 350hp with a BSFC Brake Specific Fuel Consumption of .475 at 85% IDC Injector Duty Cycle says you need 98 PPH Pounds Per Hour of fuel. Now you take you 65 PPH @ 13PSI 350 injectors and you need 30+ PSI of fuel pressure to ahcive this goal. or you could use BBC 80PPH @ 13psi injectors you need 20psi to get there.
http://www.witchhunter.com/injectorcalc1.php
Once you get that set you must make the change to the Injector Flow Rate in your .BIN, but dont expect it to run great strait out of the box. This is were the changes in the VE table must be made.