Will the stock fuel lines be enough?

[mikemustang289]

I finished my motor a month ago and have been driving it around town trying to get some miles on it. Right now it has the stock fuel system and mechanical fuel pump. I haven't beat on it very bad but the stock fuel pump seems to be getting the job done.

I purchased a 110 gph holley mechanical pump. I just want to know if the stock 5/16 fuel line is adequate. Or if there is a way to tell?

The engine is a 306, AFR 185's, 650dp carb, 221/226 .550 cam. will be shifted at 6000.

If a fuel pressure guage is recommended, which one should I purchase? The dual feed line going into the holley has a spot to mount a guage but that's kind of useless since I can't see it inside the car on a WOT run.

 

[fasttback]

You can use these rough guidelines (although there is always some variation):

Up to 250HP = 5/16" or -04 AN
Up to 375HP = 3/8" or -06 AN
Up to 550HP = 1/2" or -08 AN
Up to 800HP = 5/8" or -10 AN
Up to 1200HP = 3/4" or -12 AN

 

[69in2006]

I would highly recommend using the holley pump and it would not hurt to upgrade to 3/8 line...make sure you also install a high performance fuel filter...

 

[jcode68]

If you just put in a fresh engine and are going to replace the pump with a performance pump, I would spend the $ to replace the lines with 3/8" stainless. Especially if you have the original steel lines. Just did this on mine and was only $89 for pre bent stainless.

 

[mikemustang289]

you mind telling me where you bought your fuel lines from?

$89 sounds like a deal. Did you have to replace the sending unit as well or is that already plumed with a 3/8 pickup tube?

 

[jcode68]

you mind telling me where you bought your fuel lines from?

$89 sounds like a deal. Did you have to replace the sending unit as well or is that already plumed with a 3/8 pickup tube?

Got them from Classic Tube (www.classictube.com) and was complete for the 2 pieces from tank to fuel pump. Beware of shipping charges however. Cost another $30 due to the size of the box required to ship. Still a good buy since I didn't have to bend anything or mess with flaring fittings. Pluss they are stainless and will never need replacement. My original lines were 3/8 I believe, so I didn't replace the fitting on the sending unit.

 

[steel1212]

I'm running new 5/16 line. Why did I not buy new 3/8s, because at the time I didn't know any better.

 

[dodgestang]

I'm running new 5/16 line. Why did I not buy new 3/8s, because at the time I didn't know any better.

If it makes you feel any better my 408c laid down 396 RWHP with the 5/16 lines.

My new motor needs larger fuel lines though

 

[Vinyl66]

mikemustang289 said:
The engine is a 306, AFR 185's, 650dp carb, 221/226 .550 cam. will be shifted at 6000.

I am still using 5/16" line on my 347 with AFR185's, 650vs, 230/236 cam, shifted at 6000. I have run a best of 12.12 so far but I still haven't hit 110mph. I think I am leaving lots of HP on the table with the small fuel delivery system. I will be upgrading soon.

 

[A67StangMaster]

Got them from Classic Tube (www.classictube.com) and was complete for the 2 pieces from tank to fuel pump. Beware of shipping charges however. Cost another $30 due to the size of the box required to ship. Still a good buy since I didn't have to bend anything or mess with flaring fittings. Pluss they are stainless and will never need replacement. My original lines were 3/8 I believe, so I didn't replace the fitting on the sending unit.

I looked at there page wow 40 bucks for shipping.. still sounds good..
Subtotal: $89.00
Shipping: $39.34
Total: $128.34


This is for a 3/8 line for a 67 pre bent stainless steal

 

[SoCalCruising]

NPD, others have 3/8" sending unit for early cars. Fuel line sizes depend on your pumping system. If you run just the mechanical pump (low pressure fuel system), then you need larger line. If you run an electric pump at the tank and regulator, you can get away with smaller lines. What you need also depends on your application. A quarter mile run, or just spirited street driving is different from WOT for long stretches of road racing. For short runs, your fuel bowls act as a reserve. On longer runs, you can drain them.

 

[mikemustang289]

The reason I asked was because I plan to run the 5/16 for while until the budget allows me to upgrade. The first thing I really want to do is put on some cal-tracs because wheel hop is now a problem. I also want get some drag shocks. After that I'll plan on upgrading the lines.