UD Harold strongly suggested I install a 1/2 inch fuel line to keep my big block's 276/284 cam happily fed. But this raises a few questions:

-should I modifiy my fuel gauge sending unit's feed tube? It seems silly to have a large fuel line fed by a really small feed tube at the tank but perhaps the advantage of the 1/2 inch line is the volume of fuel existant in the line itself?

-I suppose I can have a steel line made, but would a length of braided steel line work as well?

Yes, but braided steel line is nowhere near as durable as tubing and will need to be watched for leaks over time. It also costs more.

Rich, I believe enlarging the pickup tube is a good idea. After all the original one is probably 5/16" od with a minuscule 1/4" id! I did mine last winter and it worked out pretty well.

I would use as much hard line as possible. I've experienced a lot fumes coming from the Russells #8 line that I used and plan on changing it out for something else this winter. Some other guys here have also had the same experience: http://www.chevelles.com/forum/ultimatebb.php/topic/4/21326.html

Jeff
65 Chevelle SS
454 ci
12.57 @ 114mph

sump the tank

Okay, hard line it is. How did you modify your pickup tube? I want to retain the original gauge sending unit but the tube is welded into the cover plate and the float pivot is welded to the tube.

Rich,
Assuming it's a 3/8" pickup...
What I did was cut off the external portion of the pickup tube as short as possible, but leaving enough for flaring the end for a -08AN(3/8" tube) fitting.
Then used a small section of -08 hose to attach the pickup to 1/2" hard line.
Worked fine...plentiful supply of fuel.

Rich, I made a template of the location of the bottom of the pickup tube in relationship to cover plate. I also noted on the template the location of the float arm at the end of its travel each direction (full & empty). The float assy was spot welded to the tube and I can't exactly remember how I got it off...??? Pried tube away from spot welds??? I cut off the old tube flush with the front of the cover plate and drilled the tube out of the plate. I then enlarged the hole to match the new 1/2" pickup tube. I fabbed a new line from 1/2" od steel tube to resemble the old tube but added an additional 90 degree bend on the exterior side of the cover plate to head the tube over towards the passenger side of the car. I also flared the tube to accept a #8 JIC fitting. I then silver soldered the new tube into the cover plate to match original per the template I made. The last step was to tig weld the float assy to the new tube to match original location per template. I didn't use a strainer on the end of the tube as I mounted a large Barry Grant fuel filter in the frame rail. It turned out pretty well and the fuel gauge is dead on.
I'm sure theres probably better ways to accomplish this, hopfully someone else with throw in the ideas!

Jeff

Jeff pretty well covered it. Just make sure you bend the tube just like the origonal and get the sending unit exactly in the same place. If you get good quality braided hose it will last forever. I would recommend you using #10 it is a little bigger than 1/2 and #8 is a little smaller. This is one place where bigger is better.

I modified the stock tank in my 68 Camaro by punching a hole in the front / top of the tank and installing a bulkhead connector. I'd assume that a Chevelle would be very similar.

I sealed the bulkhaed connector by using a power valve gasket on both sides (inside and outside the tank) and tightening it down real good.

The key is using a male-to-male bulhead connector and tightening the new pickup to it first. then fish the new pickup and connector into the tank through the stock opening and slide it into the new hole. Then put a gasket and nut on the outside and tighten it up.

You have to make sure that the new pickup is positioned so the the end of the tube is in the lowest part of the tank. I cut the end of my ne pickup on a 45* angle with the opening facing the back of the tank. The new pickup also needs to be positioned so that it doesn't interfer with the stock pickup and sending unit.

Here is a picture.

http://hobbystage.net/camaro/eric_68/1100206435-004931.jpg

http://hobbystage.net/camaro/eric_68/1100206947-004932.jpg

That being said, I seriously doubt you really need 1/2" line for that cam and the RPM Range. I installed my larger line to fix a low fuel pressure problem with my mechanical pump. I think if I had only switched to an electric pump and kept the 3/8" line I would have been fine.

That's about the easiest way I've seen this done, and you could still use the factory tube for a seperate nitrous fuel system.

There is a step by step article in the technical section on either Hot Rod / Car Craft or Super Chevy (the websites are the same format) website showing how to upgrade the pick-up. Has pics also.

Just an FYI.