RyaNCSU1

Im going through a H/C/I on my 87 lx. I am changing it over to carbeureted and plan on running a regulator with a bypass so I can keep the stock pump, (for now anyway). The lines all seem to be only 5/16", is that sufficient for decent power? At what point do I need to bump it to 3/8"?

tinman

Now wouldn't be a bad idea. I'd use the Aluminum line that Russel sells. Easy to work with.

RyaNCSU1

Figured 3/8 is 20% larger than 5/16" so figured I could bump the fuel pressure from 6psi to 7.5 to balance it out? Regular will adjust up to 9psi.

Did all the fuel injected engines come with 5/16" line or just the lx?

mjr46

your looking for volume not pressure, uping the pressure will cause drivibility issue and not solve a lack of volume at WOT

RyaNCSU1

so then, in your opinion i need to change to 3/8" to get the power the engine is capable of, 5/16' simply isnt big enough. fyi, currently expecting about 375 or so at the crank.

projectresto83

FYI you will start blowing seals in your regulator with your stock pump. You need to either swap to a mechanical pump (not hard at all) or run a electric pump made for carbed vehicles such as a Holley Blue. Either option is going to require you to remove the stock pump out and put a piece of hose in its place or swap over to 79-85 tank. Then get the right timing cover for a mechanical pump. The stock lines from the tank will still get you enough fuel. The feed for it is 5/16 and the return is 3/8. You can purchase adapters to attach to the stock line right by the sway bar to run a steel braided line to the carb if you want to.