Installed an edelbrock pro flo fuel injection on my motor. about to get the fuel lines run and do the gas tank mods for the return line like in the bottom of this post -

http://www.nastyz28.com/forum/showthread.php?t=37230&page=2

have a few questions, the tank has 1 nipple on the left corner, 2 on the right. They connect to hardline that seems to run up over the axle and connect to each other. Is this a vent of some sort?

second, I haven't pulled the sending unit yet to do the bulkhead mod but with the hardlines coming out of it (5/16, 3/8) and connecting to the hardlines that run up the frame to the motor, the 5/16 one has been blocked off in the engine compartment and not used. My other question is - I have to run braided fuel line for the efi pump anyways for the supply side and plan on using the original fuel supply line for the return. Can I just somehow adapt a reducer fitting to mate the 3/8 return line (originally the supply line) to the other hardline (5/16) on the sending unit and return the fuel through it instead of going through all the trouble to do the bulkhead fitting?
thanks

Eric, I'm trying to remember years ago when I did this install on my car when I ran a 383. The crux of it was though that I use the stock pickup and lines. I cut the 3/8th near the frame rail where I mounted the pump and flaired the end and hose clamped the rubber line to the 3/8th and then into the pump. Forward of that I used the rubber line to fuel rails. For the return I used the 5/16 stock line but I can't remember how I tapped into it. I beleive though that I tapped into it right where it terminated in the engine compartment.

The stock lines were enough to feed over 470 HP with upgraded 30 lb injectors. Stock injectors are 24's on the standard small block installation.

No matter HOW you try and make the stock tank work though unless you either sump and baffle the tank OR buy a Rock Valley or Ricks Stainless EFI tank you'll not want to get the tank much below 1/2 to 1/3 full otherwise it will cavitate the pump. In other words start sucking air.

The most important thing when using the stock tank and stock pickup is to mount the pump below or level with the bottom of the tank.

I don't know what the other lines are you're talking about but if it's an emissions type tank then I suspect it's the vent lines that went to the charcoal canister. Just a guess.

Thanks Rick, I was hoping you would chime in. I've got a pretty good idea how you ran your fuel system. I think eventually I will move to the EFI tank after I figure out if I like this thing.
Would you mind sharing the specs/cam on your 383 build. Give me something to look towards - have a 400 that I was hoping to build something like Marv D's Etec headed 406 and put a pro flo on it but I'd have to start all over with everything except the headers.... its only money right?