The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 06-25-2018, 12:06 PM   #1
epfatboy
Registered User
 
Join Date: Mar 2018
Location: Barrington nh
Posts: 113
LSx Conversion, fuel sending unit

Quick question:

Replaced my '74 tank with an '87 tank and sending unit. I have the Feed and return lines worked out but what is the 1/4" fitting for on the sending unit?

I'm guessing it is a vent just not sure what to do with it?

Also the near the filler on the tank and on the filler neck there is a provision for a 5/8" hose. Is that for fuel overflow? Is that also like a vent since I assume the cap is not air tight?
epfatboy is offline   Reply With Quote
Old 06-25-2018, 12:18 PM   #2
MalibuSSwagon
Registered User
 
Join Date: Sep 2009
Location: Weare,NH
Posts: 1,592
Re: LSx Conversion, fuel sending unit

The 1/4 line is for an evap. I hooked this up to the original evap line going to the engine bay but never did anything beyond that. I don't have any fuel smell issues.

Those two 5/8 fittings on the tank and the filler neck should be connected together, it's the pressure relief for when you fill the tank. Should be a factory molded hose available to connect them.
MalibuSSwagon is offline   Reply With Quote
Old 06-25-2018, 01:31 PM   #3
mongocanfly
Post Whore

 
mongocanfly's Avatar
 
Join Date: May 2015
Location: Alabama
Posts: 14,670
Re: LSx Conversion, fuel sending unit

The 1/4" on mine had a tank vent on it....nothing wrong with evap if you want....
The 5/8, Malibu covered as a tank pressure fill relief ,hooked to fill tube
__________________
Mongo...aka Greg

RIP Dad
RIP Jesse

1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598
Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334
Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563
2023 Chevy Z71..daily driver
mongocanfly is offline   Reply With Quote
Old 06-25-2018, 04:45 PM   #4
epfatboy
Registered User
 
Join Date: Mar 2018
Location: Barrington nh
Posts: 113
Re: LSx Conversion, fuel sending unit

So can I just vent it to atmosphere? Should I put a one way breather on it as well?
Posted via Mobile Device
epfatboy is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 02:43 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com