I've done both.
You need to consider the needs of the pump that will support the HP you want.

The stock unit can be modded to a 1/2 line. Just drill it out and solder in a bigger line.
Getting a tight enough bend to clear the trunk floor is the problem. The one in the picture may be tight enough.


Just noticed you have a camaro. Mine hit the trunk floor even after I dimpled it.
Needed a bigger hammer but it was starting to get a nice lump when seen from inside the trunk.

 

I am glad i went with the sump on mine. course i do this kinda fabrication for a living on aircraft, so bending/flaring .5" stainless line was no problems where it might be tough at home. also purging the tank and backfilling with argon for welding safely was another thing you might not be able to do at home so easily. here's a link to my install.

http://www.chevelles.com/forums/showthread.php?t=256632&highlight=1%2F2+fuel+system

 

I sumped my tank; and wish I hadn't.

I'd have been happier with a bigger tube going into the stock sender.

 

I sumped my tank; and wish I hadn't.

I'd have been happier with a bigger tube going into the stock sender.

why were you not happy with it?

 

1. Safety. The sump can rip off in a fairly minor collision; or get bashed on the concrete if the car goes up a steep ramp.

2. Mine is home-made; and one of the fittings leak.

Either way, fuel leaks aren't fun.

 

Thanks for being realistic about this. I thought the same thing before I got to your post. Sure, a rear ender may damage your take. But elbows will fracture off long before an unmodified tank will rupture. Lots of liability hanging out there... Be careful!

 

I did a sump, but it was on a new tank so it was much easier. Competition products offeres 1/2 or 3/8, but not a combo. Would need an adapter to run 3/8 return back in-maybe just the smaller fitting on end of line.

 

I have a 70 chevelle,originally a 307 car what size would the factory fuel line be?

 

Could be wrong but more than likely it's a 5/16" line

-Bobby-

 

If it's a street oriented car go with the stock sending unit design.

For a fast street/race do the sump or save your money and just buy a cell. It can actually be mounted in the trunk.

Some people like seeing all the sump, lines, filters and pump hanging under the car, but I think it looks cheap, sort of a lackluster design.

-Bobby-

 

Here is info on modifying a stock sending unit for 1/2

http://www.novas.net/forums/showthread.php?t=327&highlight=sending+unit

 

I have a robbmc unti. It works great. I also like that you can't see it. With the sump, it's pretty obvious. I got the robmc unit with female AN fittings. Worked great.

If you want the stealth look go with the robbmc unit. Worth the price, IMHO.

 

i have a factory 70 chevelle tank with a sump added thats been pro done. used to be on my 9 sec race car. the sides have been narrowed slightly and the filler neck has been moved to go up through the factory body plug in the trunk so fuel doesnt run out every pass. would make you a heck of a deal on it

 

I soldered in a 1/2" line to my stock sending unit. Works great and was pretty simple. Took out a 5/16 tube with a sock on it. bent a 1/2" stainless line the same shape and soldered it in place with a big 300 watt soldering iron.