Author Topic: Ls Swap Info  (Read 8429 times)

Offline youngboyinthe74

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Ls Swap Info
« on: December 03, 2013, 12:38:09 AM »
Hey fellas, I'm doing a 5.3L swap on my 74 and have a question about the fuel tank sending unit. I'm using the 87 gas tank and sending unit with AN steel braided line and a walbro in tank pump. How do I adapt the hoses to fit the sending unit? Or can I simply just clamp them on? anyone have the Pn# for the fittings? or a pic of it would help

Please and Thank You for Assistance.

Offline Captkaos

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Re: Ls Swap Info
« Reply #1 on: December 04, 2013, 08:07:42 PM »
I get all my stuff from Pure Choice: You want all 4 PN's listed on this page:
http://www.purechoicemotorsports.com/index.cfm/page/ptype=product/product_id=310/category_id=132/home_id=97/mode=prod/prd310.htm
 
For the factory fuel rail.
P/N   5810       3/8" tube (green clip)
P/N   5820       5/16" tube (blue clip)


For the sending unit:
P/N   5860      14mm female (return line)
P/N   5870      16mm female (feed line)

This is on my tank:






Offline youngboyinthe74

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Re: Ls Swap Info
« Reply #2 on: January 06, 2014, 11:22:19 PM »
appreciate that info. now I pick up where I left off.

Offline youngboyinthe74

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Re: Ls Swap Info
« Reply #3 on: February 22, 2014, 11:44:06 PM »
Hey man, what do I use to seal the fitting to the sending unit?

Offline Captkaos

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Re: Ls Swap Info
« Reply #4 on: March 04, 2014, 09:11:44 PM »
which sending unit?  There are 2 types.  the pickup has slip on, the blazer/burb has metric thread, what I posted goes on the burb.

The ones for a pickup would be http://www.jegs.com/i/Earls/361/165006/10002/-1?parentProductId=749418

Offline lukessguare

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Re: Ls Swap Info
« Reply #5 on: March 17, 2014, 07:09:05 PM »
I'm guessing the newer pumps fit the older sending units. Cause 87 put out 9-13 lbs. Not nearly enough for ls series.  I'm wanting the 4.8 ls but not sure i can figure out the wiring and Carb intake is as much as the motor. Good luck. It'll be awesome

Offline Captkaos

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Re: Ls Swap Info
« Reply #6 on: March 24, 2014, 11:10:01 PM »
The electric pumps from 87-up will fit a 1987 sending unit from a TBI pump, some have to be modified, but the EP 241 will fit fine, but it is rated up to about 60lbs.  The EP381 is the same factory pump the Grand National and Sy/Ty guys use so it should have enough volume for about 400hp NA.

This is an EP 381 pump with what needs to be modified to work, note one tang is cut off:


This is a side beside comparison of the 241 vs the 381, AFTER I cut the above tangs off:


This is a Walbro 255lph pump on a 1987 sending unit, should be good for about 500hp NA


This is a Walbro 430lph fat bottom pump (E85) on a custom Racetronix mount on a factory sending unit: