How much hp can the stock lines support?
 

I was thinking of updated the fuel lines. It's not that expexsive if you run 3/8" lines. Those 1/2" lines are not bad till you start getting into the fittings.

My idea is to leave the 3/8" stock feed line and use that as my return line. Then replace the tiny stock return line with aluminum 3/8" line and use that to feed the carb.

So how much can the 3/8" line support? My fuel system will consist of an
accel 74701 efi pump that can supply enough fuel for 400 hp naturally and 330 forced to a fuel injections set up. Figured that might equal a little more if its carbed. Im shooting for 250~300 just want to make sure the fuel system will be up to par.

I'm using the stock lines on my piston swap, making 420hp at the wheels. I'm using a walbro 255hp pump in the location of the stock low pressure inline pump.

I'm not even sure what the pickup in the tank looks like though.

Later
Randy

8mm (5/16) fuel lines aren't a problem up to about 400-450hp.

I suspect the reason why 1/2" fuel lines used to be so popular, is because the cars in question were using front mounted fuel pumps that had to draw the fuel through. Cavitation was probably a problem with the necessarily long section of fuel line that was under suction.

yah, 450 to 500 hp...... i dont think your there yet.... spend your money on cheese , and get fat!!!

I'm building a 450-500hp setup, and replacing the standard delivery line with 1/2", and using the stock delivery line as a return. I'm getting the tank modified with two 1/2" pickups so I can run two 255 Walbro pumps into the single fuel line.

Im still running the stock feed line,with another stock feed line next to it for the return.TII cars run the same size lines,and there are lots of people running 350-400hp through them.Just be sure your pump can maintain pressure,and youll be fine.

I have 480rwhp with stock lines. As the others have said, it will be fine.