Fuel line help?

Engine and tranny are out of car...just wondering if the stock 5/16 fuel line is going to flow enough for a 360 or 408. Plan to use a holley mechanical pump and 750 holley carb. Also do I need to do away with the return line and use a vented gas cap? Any suggestions would be appreciated. What material should I use if changing to 3/8 line?

Put at least a 3/8' line on it along with a minimum 3/8" sending unit. 5/16" might feed it, but why chance it. I've done a number of test with nothing but a feed line change and the results were NEVER worse with a larger feed line.

You can buy bulk steel line at Napa or any well stocked auto parts house. Use the old line as a template. Get a tube bender which is relatively cheap.

You can get formed steel lines from a number of vendors. Aluminum line works and is about $20-25 from summit. If you go with the tube nuts/sleeves, cost adds up fast.

If you drive it on the street a lot, I'd go with a steel line for durability.