When installing Edelbrock's Pro-Flo on my 81' Camaro, I installed the in-line fuel pump and added a return line to the stock tank using the directions included in Edelbrock's manual (pages 15-18) I used the stock supply line as the return line and installed a new 3/8" supply line. The stock pickup will still be used with the new supply line.
An externally mounted in-line pump like the MSD #2225 will work and is $90 at Summit. You can also get one similar that will work at Carquest, P/N E8248 for about the same price. I bought one and it works fine with my 383 SBC MPFI system and has a lifetime warranty.
I followed Edelbrock's instructions and used the original pick-up sock in my 81' tank and have never had a fuel starvation problem. This does not require having a sump installed which obviously saves cost. The cheapest route would be to use the original sock and external pump.
THanks Ed... I just gotta figure out how to mount the sending unit.. Obviously, if I have to drill a hole for it and stuff, then once it is done the tank will have to be sent out to be cleaned so no metal particles wind up in the lines... Anyone have an idea what that usually costs?? TO have the tank professionally cleaned? Its a relatively new tank, so there is no rust problem..
Also, what size Feed Line should I use?? I will most likely just bend my own steel line. I went through all that braided hose nonsense on my last project and it just cost too much once I was done with all the line & fittings..
What size feed would be good enough for a stock motor? I will use the stock line that is there now for the return, like the edelbrock instructions suggest.. makes sense..
Then again, the stock motor in my car was a v-6.. So is the line smaller than a stock line from a Z28?
I do not know what size the V6 pickup is, but my V8 pickup is 3/8". That is all that is needed for your V8. Hopefully your's is 3/8" as well. The return line only needs to be 5/16", but 3/8" works also. Be sure to replace the pickup sock. They are like $5 and are a slip on connection.
You do not need to drill any part of the tank. Drop the tank and remove the entire sending unit. I used the bulkhead method (see bottom picture), but made it up using brass fittings from a local hardware store. Drill a hole in the top of the sending unit plate just big enough for the threaded part of the 90* fitting to fit. Imagine in the picture below (right) that a the hole is drilled directly to the left of the pickup tube. By having the top 90* piece penetrate the top of the sending unit with a male end, the female coupling can be used as a nut. Tighten snug with a gas resistant gasket between the bottom of the sending unit and the coupling.
So the original supply line running up to the engine bay will be used as the return line, but will be connected to the new bulkhead fitting with some rubber hose. This is a low pressure side so regular fuel line is fine. However, you should use a section of hard 3/8" line between the bulkhead fitting to the front edge of the tank. This is because it is a very tight squeeze between the top of the tank and the trunk. It will literally squeeze a rubber hose up there. A short section of hose with clamps between nipples is fine.
I ran a new 3/8" supply line using the fuel injection hose that came with the Edelbrock Pro-Flo kit. This can also be purchased at a local supply store. I know Pep Boys carries it, but it is very expensive (like $3 a foot). So you might be better served to bend a new hard line and use a section of high pressure fuel injection hose between the engine and new line. You would also connect the new supply line to the original pickup line with some hose. Everywhere I have rubber line connected to hard line I have a brass compression fitting connected to the hard line with a threaded nipple for the hose end. Just be sure to have high pressure hose whenever rubber hose is located between the pump and regulator.
I hope this makes sense; I wish I had taken some pictures of the installation in detail. If you have any more questions, just ask. Ed