Well I'm elbow deep into this ls1 swap and could use a little advise on how to get my fuel lines back together. I have the 4th gen fuel tank and I kept the rear section and the front section of the 4th gen hard lines. I just need to connect the hard lines back together. Can I just use compression fittings or do I need to try to flare the lines and use AN fittings??? Thanks

I did both. Either one will work.

Thanks, hopefully will have this swap drivable sometime next month. I have read alot about the fuel lines on here and was wondering about my lines. My car is a factory 1991 3.1 car and appears to have a feed and a return line. The fourth gen plastic tank has 3 lines ( the extra just connects at the rear by the T in the Filter). The engine I have is out of a 2001 Z28 and has two lines coming off of it but looks like most everyone on here just has one line running to their engine. Can I just reconnect to my lines or do I have to just use 1 line at the engine???

2001 would have one fuel feed line at the engine, and a vapor line taped together with it. The return line at the 4th gen plastic tank does the pressure controlling.

I put a "T" after the filter to go back to the 4th gen return on the LS1/T56 car. In the LS1/4L60E car, I kept the 3rd gen tank and used a Vette filter which has the pressure control built into it.

Well I thought I had the lines figured out now I'm lost again. I thought the second line at the engine was the return line. What is the vapor line for and what do I need to do with it. Mine is the ls1 with a 4l60e and I already have the 4th gen tank installed. I appreciate the help, this project has been a little overwelming at times. I'm also installing the 4th gen dash and hvac box along with the bmw headlights and most everything else off the 4th gen.

I should have called it vapor recovery, I think. It purges the vapor canister on the tank as commanded by the PCM.

Before I go trying something else, could u tell me if this route should work? The 3 lines off the plastic tank, I plan on hooking up like factory.One goes to the filter and then to the engine. One goes to a tee by the filter (which I'm guessing is the return line) the last one must go to the vapor recovery that was mentioned. As long as they are routed like that (which is how they were on the 4th gen I think) will that work??? Thank you again

If it was a 3.1 car, there should be 3 lines going to the front of the car originally. A feed line, a return line that came straight up close to the brake booster that had rubber hoses that screwed to them, and the line that went to the charcoal canister for the purge.

Yeah it had the small line that crossed over the front of the tranny tunnel to the charcoal cannister but I wasn't planning on using it for anything and removed it. I wasn't counting that one due to its size, haha. I think I've got if figured out for the most part. I'm still not sure if I should be thanking you guys or cussing at some of you LOL. I bought the 2001 just planning on installing the motor and tranny and a friend turned me on to this site, that seems like a LONG time ago. I have alot of interesting things done to my car and not much left thats still 3rd gen other than the body. There are alot of creative people on here and I can't wait till I can get this thing fired up. Once again thanks for you helpfel comments.