I guess that my first major question is...

Will -6 AN or 3/8 fuel line be adequate to support my 383 stroker that makes 500HP/517TQ?

The reason why I am asking is this. My current fuel system setup is a factory tank with a modified sending unit to allow -8 AN line. The OEM fuel pump(EFI) has been removed and a 1/2 in stainless steel tube acts as the pickup ending where the pump sock would have been. I am running -8 stainless steel braided hose from the tank to the inlet of a Holley mechanical fuel pump that has a 3/8 inlet/outlet. Then, I have -6 AN line coming out of the fuel pump and into my fuel log and feeds a Holley 750 Street HP 4150 series carb. Under full throttle the carb runs out of gas and I don't think that the mechanical pump can keep up with the needed fuel flow, due to the fact that fuel pressure remains steady at 4.5 PSI, and I am pretty sure that the issue is with volume not pressure. Needless to say my gas tank is now leaking and I need a new one. I have been thinking about putting in another tank and using a Walbro/Racetronix pump with the Russel quick connect fittings and run -6 stainless all the way up to a regulator set to 7.5 PSI, then continue that to the fuel log/carb. I am just worried that the -6 feed might not be big enough to satisfy my engine's fuel demands. Any thoughts??

 

I was running my 500 HP 396 (400 HP + 100 shot) with 3/8" line, on E85 (requires ~1/3 more volume than gasoline).

If your fuel pressure stays at 4.5 psi when the carb seems to "run out of gas", then your problem is most likely at the carb inlet(s). Either plugged inlet filters, improperly set float levels, or you need larger needle/seats (I had larger needle/seats in my E85 carb).

Do you have any sort of exhaust monitoring (O2 or EGT) to confirm that it's going lean on you?

 

five seven- unfortunately i do not have any o2 sensors to actually see that its going lean. My problem only happens at WOT, and after I get to the top of 2nd gear at 5000+ RPM. It literally feels like I took my foot off of the gas pedal. The fuel log that I am using in this..

http://www.jegs.com/i/Russell/799/64...oductId=743845

Needless to say I only have about 100 miles on the carb and the fuel log. The carb I bought is a remanufactured unit directly from Holley. I think I might have an issue with the small section of -6 that goes from the pump outlet to the fuel log inlet which is -8. Maybe the log isn't getting filled up with fuel all the way? For simplicty's sake I would like to stick with a mechanical pump, but if the pumps keep dying then obviously it isn't a good choice. I did see that Aeromotive has a high volume mechanical pump for the SBC that has a -10 inlet and a -8 outlet. Maybe that might work better? Otherwise, if I go electrical I'd have to rewire in relays, get a new sender, rerun supply AND return lines and a bunch of other stuff...

On a side note, the old Edelbrock 750 CFM manual choke carb that I had on there before made 419 rear wheel HP and 430 rear wheel TQ and never had any issues with fuel at WOT. I wonder what the possibility could be that the Edelbrock was holding back engine power, and now that I have a much better flowing Holley unit the fuel system is not adequate.