EFI Fuel System

The best system is an in-tank pump (with a tank with baffles, these are sold now - I have an Aeromotive Phantom system that basically does the same thing), feed/return wth the regulator after the rails. Mine is 3/8" feed and return, you could probably get away with a 5/16" return if you needed to but just don't use a huge pump then.

The pump being in the tank keeps the pump cool (it will last longer), full return system eliminates vapor lock and provides precise control of the fuel pressure after the injectors, so there's no fluxuations at the injectors during transients. You can also run an inline fuel filter and you won't get no-starts unless its totally clogged.

The "corvette" system is just an orifice/controlled leak. They also used these on Saturns. Aftermarket parts may be not as good quality and as mentioned the pressure is higher, but can also be influenced by the pump (a big pump may mean higher pressure than intended). They did this to be cheap and for no other reason.

I have seen a lot of people quit on EFI and when you look at the trace it is either not picking up fuel due to sloshing with the stock pickup or they get strange pressure drops due to the returnless system or poor pump mounting.