OBS to LQ4 Fuel system

[RedHeartbeat]

All the GM rubber lines are fine unless they're brittle. I've never had one fail, yet. Knock on wood. I don't flare the lines when I cut them, just double clamp each end of the rubber line on the connections. I don't use the worm gear clamps that cut up the rubber lines, I use the smooth wall clamps that have a nut and bolt through them to draw them up tight without cutting the surrounding rubber. Some high quality stuff like Russell connections and hose would be the best way to do your connections. Even a tractor supply company could build you some hose assemblies up for the fuel. NAPA is also a good source for the fuel lines, hose and custom crimping.

[watdog]

So I picked up some parts and the inlet side going to the fuel rails uses a 3/8 snap lock fitting. On what looks like the return side is a 5/16 snap lock fitting.

I checked out the corvette fuel filter and it has the same style fittings 1 is a 3/8 snap lock and the other was a 5/16 fitting. The other side said outlet which was really confusing to me what type of fitting would go in that side.

My understanding from your posts is do not cut the metal tubing but the rubber tubing leading up the firewall can be modified and install higher pressure fuel lines to the engine from that point.

[RedHeartbeat]

No need to cut anything but the ends of the hoses that used to go to the throttle body on the old engine. You don't have a need for the Corvette fuel filter, the stock filter will work fine. Take your tubing cutter and cut the ends off the old connections, remove the threaded fitting and apply a piece of hose to connect it to the snap-loc fitting(3/8" to 3/8" and 5/16" to 5/16"). The stock return line will return excess fuel pressure to the fuel tank. Depending on how long your hoses are you could cut the rubber hose and use it or you could cut the metal tube and join it to the snap-loc fittings.

[watdog]

So we are going to cut right behind the old connectors. Right at the back of the block. Then install the snap lock fittings and run that to the rail. We may need to install an extension piece but it looks good. The old system was fuel injected but at a lower pressure I think it was 28-32psi maybe. Do you think those flex lines will be ok? They look fine but not sure if they will be able to take the extra pressure.

[RedHeartbeat]

They should be able to handle the pressure. The lines at the fuel tank are made of the same stuff and all us guys with the OBS trucks have never replaced them that I know of.