3/8" or 1/2" fuel line for a 505

Starting on our 71 RR, engine is a 10.7 Cr 440 stroker in front of a built 727 and 3.54s, Beefed up 11" convertor

Dynoed at 620 HP, 640 TQ, RPMs limit at 6000. Solid roller.

This is primarily a street car, 4000# may be one or two outings to sort out suspension etc.

Electric pump only, single 950, dual plane MW Indy, Max wedge Victors.

I'm thinking 3/8" should suffice, but before I spring for the lines, I thought I'd see what the masters think.

Thanks, Joe

3/8" will probably suffice, so get 1/2" so it's not questionable.

I have 1/2" on my 451. I don't like having to buy things twice

Haven't looked yet, but does Fine Lines supply a !/2"?

Also, what do I do for a sending unit, redo a 3/8"?

Std tank.

Thanks, Joe

Put a new 1/2" pickup at the bottom rear of the tank? yes, it takes work.

I've done both, but have fed a stout 512 with 3/8" and a good mech pump & regulator without issues.
For a street car I wouldn't worry about the 1/2".
For dual quads, high RPM, or drag racing, I'd go 1/2".

Nicely made(no kinks) 3/8 is fine.. one kink and your done.. a few places make 3/8 pick ups..
I use to make my own

3/8" will be more than enough.

For a street car 3/8. If you expect hard launches, then 1/2. When you launch, you need to overcome the force that pushes you back in the seat. It does the same thing to the fuel in the line. Bowls are full at the launch and run out of fuel pretty fast. The more volume in the line, the easier it is to recoop that inertia of the launch. Its only an 1/8 larger so no big difference in cost. One less issue to think about when you are sorting things out.

Hey Joe I don't know where you are in Ohio but you can pick up your lines at Fine Lines direct in Wadsworth and avoid the lines bent in half when they ship them. I had 3/8" on my Savoy when I had a 440 in it and when I changed to a high volume pump and 493 I switched to 1/2". I never had issues with the smaller line I just was changing every thing else in the fuel system so I just upgraded to a cleaner system with smoother bends

Gus

Pretty sure Vans Auto has the 1/2 inch pickups in stock.

Just a short story. Ron mancini had a b-1 powered car that made around 950 hp. It had two carter fuel pumps and 3/8 line. So someone told him he would pick up big time going to 1/2 and a better fuel system. He went complete system with 1/2 with magna fuel system. Never picked up at all. So to answer your question 3/8 will be fine.

Are you talking about the outside diameter or inside diameter of the new line?
if inside diameter 3/8 inch is fine, if outside diameter go with the 1/2 inch
What brand and size electric pump are you going too use?
Not all of them work good

Cab.. tubing is measured on the OD.. 3/8 will work fine for a street car

Mine is similar to yours in a lot of ways. 508 street car, small roller, shift around 6400, Indy dual plane, 950 carb with 0.110" N&S, stock converter. 4150 lbs and runs in the high 11s at 120 mph with a 1.9 sec 60 ft.

I have 3/8" line and a Mallory 140 pump regulated to 6 psi. It runs about 4 psi down the track and through the traps. If you're lifting the tires off the ground, consider 1/2".

I've posted it here before and people tend not to believe so....

I've ran 11.19 @ 121 mph in a 3,600 lbs. car with the slant 6 OE 5/16 fuel line from tank to Carter street/strip pump. 3/8 from pump to carb. Stock (replacement) tank and pickup.

Thanks guys, I've decided 3/8.

Thanks fourgear, I am picking up from fineLines, an hour drive for me,
did the same for our 440 Charger.

Thank you all for your input.

Joe