I have a stock 502 what size an fittings should I run? -6 or -8 I'm guessing? Any help is really appreciated

You might wanna specify to what and for what

Sorry fuel lines 850 holley

-6 will work. If you do go braided ss use the Teflon lined stuff.
http://ipgparts.com/blog/fuel-line-s...ize-do-i-need/

imo -6 will work but if it is new plumbing -8 only cost a few bucks more so why not use -8?

I'm assuming that you are running a Holley style carb. I would run #8 from the pump/filter to the carb manifold/regulator and #6 to each bowl. just my opinion.

I would plumb from the tank to the filter and the filter to the pump in -10. Then plumb from the pump to the carb with -8. You never know what the future may hold for power upgrades so make the lines big enough so that you won't have to do it again in the future. It will only cost a few extra dollars to plumb it in the larger lines now so that you won't have to redo it in the future if you make some upgrades.
Eddie

Just curious, what size pick up is in the tank ?

Thats pretty much my setup right there. works nicely.

Ok thanks so I guess 8 is a safe number I have accepted the fact that I don't have a fast boat and if I want to go fast I'm putting more power in a different boat. Whatever lines I put in it are gonna be going with the same power I have in it until I get a new boat. So just for simplicity I'll probably stick with one size