Thanks for posting on /r/MechanicAdvice! This is just a reminder to review the [rules](https://www.reddit.com/r/MechanicAdvice/about/rules/). If you are here asking about a second opinion (ie "Is the shop trying to fleece me?"), please read through CJM8515's [post on the subject.](https://www.reddit.com/r/MechanicAdvice/comments/4qblei/fyi_the_shop_isnt_likely_trying_to_rip_you_off/) and remember rule 3a, please post the year/make/model of the vehicle you are working on. **If this post is about bodywork, accident damage, paint, dent/ding, questions it belongs in /r/AutoBody or /r/Diyautobody If you have tire questions check out https://www.reddit.com/r/MechanicAdvice/comments/k9ll55/can_your_tire_be_repaired/**. If you dont have a question and you're just showing off it belongs in /r/Justrolledintotheshop This is an automated reply *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/MechanicAdvice) if you have any questions or concerns.*


Is there a pressure sensor at the other end of either of the fuel rails?


No there’s not. I had a feeling something was missing and I think that’s it. I kept telling my girlfriend that my mind was drawing a blank on what I was missing.


But shouldn’t there be a second line below on the fuel rail for the return line to connect to?


Will the 99 fuel rail bolt to the 04?


The whole engine is from the 04 including the intake. Silverado doesn’t have a engine, which is why I’m throwing this one in it


In the early 2000s just about all manufacturers switched to a returnless system. There is just one line to the engine, and the pressure regulator is in the tank as part of the fuel pump module. A lot also went to electronic throttles at this point too. You'll need an intake and fuel rails from a 99 to make it all work nicely.


Okay that kinda what I thought I was going to end up having to do. Appreciate you and everyone else for taking the time to offer some advice!!


You were completely right. Just to give a update to anyone else who needs the help. Around 2004 (which is what my engine is out of) they went to return less fuel system. So if you have a 99-2003 Silverado, Sierra, Yukon, or Tahoe and you’re trying to do a engine swap with a 2004 and up Vortec engine, be sure to get a different fuel injection rail and throttle body. Thanks 4x4Welder